Granted that these maps are far from perfect, tryharding makes people leave more than the map itself. The lack of an op spot shouldn't be the justification for the removal of a map, and being "boring" is something subjective too. One of the office maps, for example, might be boring for us experienced players, but it might be some new player's favourite. Moreover I personally think ph_awesomebuilding is boring for example, but I wouldn't put it up for removal for that reason alone, and that one also makes people leave when you hide in an op spot and don't taunt.
Lastly, since we're experiencing an enormous wave of new players, removing the easy maps would just be the stupidest idea ever.