Well, I think, the term "spawncamp" can be split according to several situations and the answer to "Ban?" depends on the situation.
a) It is obvious that a spawn was build by a griefer, like a telenode in front of the alien base.
In this case, the correct way of acting whould be to destroy the spawn asap, as there is no "proper builder" responsible for this. A kick should hit spawncampers and the griefer in this casebecause I consider the spawncamping as an important part of the griefing in this case.
b) The spawn was built by a proper builder in a bad location, so a dretch can sit on it or a human can snipe dretches coming out of it.
Well, as long as the team has a greater advantage from camping than the advantage from destroying it, it is legal in my opinion. A dretch is unable to kill a telenode, but it can sit on it and headchomp anyone coming out of it, if the human team is unable to kill it, it is their fault. However, if this is the last telenode, there is no advantage from camping longer than 2 - 3 kills, because then the dretch can evolve and kill it. Same with a bad egg, camp it, if thats better than killing it. Getting S2 fast as a human is a big advantage.
Thus, a kick should only occur if there is no real advantage from camping the spawns. If there is an advantage, it is a legal tactic.