I don´t think that you can compare DB with CS or Dota. Both games actually exist for a long time and because of that many different mechanics apply to the development of there playerbase. Anyways, the thing is that those mechanics shouldn´t be effecting DB since most players (at least those who are playing) are relatively new. Obviously DB suffers from its development state that causes negative effects like bad performance and so on… So it´s hard to really judge those playerbase developments. What frightens me tho, is that the numbers are going down steadily. It´s not like people come in waves and leave because they don´t like it, the performance is too bad etc… No, the people who are coming in generally seem to like the concept of the game (after all they signed up for it) and try to give it a chance but get bored relatively fast.
I have been following the WoW development, and there reasoning and methods for holding players etc. for a long time. In the general opinion, the biggest reason for why WoW has declining numbers for years now, is that the replayablity is sinking. At first stance most addons and patches are actually great. A lot of people are usually coming back at times where those get released. Sometimes even more then Blizzard is expecting… But once people have seen everything that there is new to the game - they leave it again. And I think the reason for why we have those declining numbers in DB is mostly due to the very low replayability as well.
Once I have played the current map pool 2 or 3 times in a row, I am done. It feels as if I have seen everything that there is to the game. Probably that is not true, and I just don´t understand the more complex levels of the game and the meta that comes along with it. Maybe this is because I expect to be a complex team game like ET:QW was. But regardless how often I come back and how many chances I give it or how many friends I invite. We all end up playing something else. And that is by no means because DB is bad, it´s just because DB doesn´t offer this replayablity.
I am really wondering how you make people to play the same thing over and over again… And I think that one of the, if not THE main thing to consider is the diversity you experience within the game. A game that is supposed to be played over and over again HAS to offer various decisions and ways to go in order to achieve a goal. Playing always involves options. You need to be able to choose what you do and how you do it. That doesn´t mean that games that don´t offer you this kind of freedom are bad - they just aren´t gojng to be replayed that often. Those options, and there impact on the game are very minor in DB. To show this I am going to compare those to CS:GO, ET:QW as well as Mobas.
CS:GO:
-) What to buy at the beginning of every round (large impact, quiet linear tho)
-) Where to go and how to engage or position yourself (massive impact and also offering insane pool of options while being relevent for the most time of the game and crucial for EVERY single engagement with the enemy)
-) How to coordinate your team (large to massive impact and mostly adding diversity on a teamplay level when playing with friends etc.)
-) What role do you play right now (medium impact but still, identifying your role in a current round or lineup gives a unique flavour to every game and also can be in some cases a win condition, however it is quiet linear and mostly evolves around some of the points I mentioned earlier alongside with a different mindset).
ET:QW:
-) What class to pick and where to spawn (generally low impact and linear, but potentially game changing and required high skill of judgment in hectic situations)
-) Where to go and how to engage or position yourself (low to medium impact on individual level, still crucial at situations where you need to make a play but overall not too impactfull)
-) How to coordinate your team (insane impact, continuously adjusting your positioning and playstyle as a team is absolutely key)
-) What role do you play right now (high impact, due to the relevance of switching classes, the game situations and your own performance there are actually multiple roles you can fulfill during a game)
Mobas:
-) What class to pick (high impact, but very linear since you have to follow at least some sort of meta)
-) Where to go and how to engage or position yourself (high impact, needs a lot of skill only few people in the world have actually mastered this - so much depth there is to it)
-) How to coordinate your team (insane impact, from minute 1 until the end of the game you need to know what your objectives as a team are and again due to it´s complexity only few teams in the world actually can be considered as good in doing so)
-) What role do you play right now (high impact, according to your picked class there may be various roles you can fulfill, identifying which role your team needs you to fulfill and being able to execute it is again something only few people really are able to do)
DB (my judgments may be little off at this one… correct me if i am wrong):
-) What class to pick and which loadout (medium to high impact, for the objective part of the game mostly irrelevant, in therms of team lineup decently impact full but overall really not that game changing as long as you manage to kill something…)
-) Where to go and how to engage or position yourself (low impact, on a team level almost no impact as long as you go together, individually some impact and in clutch situations potentially decent impact)
-) How to coordinate your team (medium impact, it´s still important to understand if you need to be aggressive or rather defensive as a team, but sadly there aren´t many wasy to actually executy various positionings and tactics)
-) What role do you play right now (medium to high impact, according to the gamesituation and your current performance there may be different roles you are better at then others but in case of DB the possibilities are very limited)
Overall your options are very limited in DB and mostly not that impactfull. Regardless if on indivudual or on a team basis, besides switching your class, and the general role you have in the current situation/game and VERY FEW positions and ways to engage there is almost no diversity at all. I am not going to count loadouts here, which are going to be mostly purchasable… Because of that the fun you will have after playing it over and over again will decline rapidly with time, since the potential game situations and decisions that come along with it aren´t there and the game ends to be a linear run and gun - in my eyes a horrible combination. Sure some people are still going to enjoy it, but if that´s going to be enough for them to spend some money and overall to keep a f2p alive… I don´t know.
As far as I understand the current situation, we either need a much, much, MUCH deeper character customization (more in direction of a moba) or more tactical FPS elements (those can come from general gameplay and/or map changes). And since Overwatch is going to be out sooner or later, I really hope that DB will make the shift towards more team and tactical oriented gameplay. Because making a rather “casual” game that is similar to an upcoming Blizzard game is going to be a disaster. No offense SD but they have proven to be good in doing such games repeatedly and probably have a much higher budget on top of that…
cheers,
onYn
PS: That post originally was supposed to be a reply to another post… Because of that the beginning seems a little bit off 
