This is a common theme in SD maps (going way back to their first RTCW maps and ET’s standard maps). SD maps seem to adhere to the concept that the fun is in playing them, not in completing them. They only made one good competitive ET map (Radar) and I bet that was an accident.
At the risk of blowing my own trumpet it was all explained here :-
http://forums.warchest.com/showthread.php/7378-ET-competition-maps-guidelines
In particular the “spawn rule”.
In XT spawns are too short, travel distance (for defenders) too short, and often the time it takes to complete the objective (EV repair time, C4 fuse time) is too long. Defenders get too many chances to recover from attackers wiping them out, taking control of an area, and it’s this that leads to both the meat-grinder effect and the underwhelming sense of (non)achievement when whatever it is you’re trying to do eventually (and seemingly by pure luck) gets done.
There’s no wow factor, no “**** me that was a good game” feeling at the end. No “moment in time” when the game is won or lost, it just ends, often before final objective, and you’re left checking the score board to see who won.