Well yeah, if you're taking over a base.. you HAVE to spawn kill... simply because if you don't, you then die, and you don't get to take over the base that could be crucial to turning the tides in the game.
Aside from this though.. I can't stand people who spawn. I mean if you're evenly matched... why are you spawning? Evenly matched means that it should be a kick ass game.. by spawning you ruin that perfect balance.
All aside, I wish more games did something to prevent spawning. Like in tribes2... lots of people implemented about 3 seconds of invisibility.. so even if you do spawn, people don't know it so you can run off before they have a chance. In Purge... you are invulnerable until you move (don't move within a minute and it drops you), but then once you move you have about 6 seconds of invincibility, or a certain distance (so youcan't run across the map). As soon as you shoot it drops to about 2 seconds. This is great cause if you attempt to spawn them.. you'll die instead...
See with BF1942.. When I get spawned.. I die before my camera has a chance to switch to First Person.. its still in free look, and I die.. That's not right. 2-3 seconds of invulnrability or something so you can run away would be a lot nicer... but again it wouln't for when you take over a base and enemies spawn at the last possible second.. as then you can't kill them.
Erg the limitation to keep a game cool sometimes end up leaving room for cheap "Gamers"