Some thoughts.

I have seen good players being accused of team stacking upon joining the game on the middle of the map. It's like they have to wait for available slot in another team to join or wait for the next map, so they can be cool with you, raging about unfairness. Another thing I've heard - "you just joined this team because it will be switched next round and you will go CT on Aztec", or "you just joined CT on aztec, Stacker", so what do you want from good players now, should they just quit? I know we used to have issues with team stackers before we implemented team switching plug-in, even after it, it was a bit unfair due to a bad timing, but it was recently fixed. The only form of map stacking I see is when players intentionally join back to another side after teams got switched, but don't worry about this one, it's very rare, just leave it up for admins to deal with.
Bottom line, if you can't get a kill, don't look for someone guilty in this, work harder to get better.