The problem you would then have is focus. In the days of ET, you would have an autoexec set up for each map and a pre-defined set of keys so for example if someone wanted to spawn at the rear spawn they would press f1 …second spawn f2, or you could have it cycle so spawn point 3 would be 3 presses. In the case of the forward spawn capture in the video you would hit one key and /kill. If you for some reason later in the game wanted to spawn at that forward spawn instead of the cp, you would use your other binds to toggle between spawn points, then /kill.
Introducing a vote option or something similar, whilst on the face of it would work, in actual gameplay it would take your mind off the game by forcing you to read the message, make choices as to what to do, etc etc. /kill as it was would be a better system since you would default to the spawn point just captured, and without the worry of timers etc.
Having said that, until SD improve the maps, make them larger with forward and rear spawns or alternative routes, the value of /kill is massively watered down whatever system is in place