In your situation, one team wants to win engagements in a way that allows for spawn trapping for as long as they can keep the trap going. Makes sense. But the strategy doesn't end there. Players are going to want to find ways to prevent or stop the traps, then also find ways to prevent the preventing so they can keep trapping, and so on, and so on.
Eventually, players are going to be "pushed" to find strategies that make the concept of spawn trapping seem wholesome and fair - and the cycle will continue. Players will explore the game's depth and push the game forward. That's real strategy.
Who is a strong player? A strong player someone who consistently wins against all others. A strong player will not give you a chance, and he will do every legal move that the game allows in order to win. I have no respect for someone who plays by made-up rules to follow some kind of "honor" and holds himself back (I mean this as a player, I don't lose respect for anyone as a person based on how they play a videogame).
All that being said, what is NOT awesome is a team of 6 hardcore guys vs a team of 6 random newbies playing the demo. That happens WAY too much in this game, and it's a problem that must be solved.
This all brings me back to the point I keep making about Motivator camping. Motivator camping just happens to be the "now" thing. Just like your spawn trap example, the community needs to start applying tactics to stop camping, to stop the stopping, etc so this game can move forward. I know how to beat it, and I've been trying to guide people in the right direction for a while now, but everyone's content to just complain about it instead of trying to win and I'm usually flamed for being a 'booster' or something dumb like that. If the community at large allows the game to stagnate here at the camping stage, then the community deserves all the problems it faces because of it.
However, if people start adopting the Motivator as part of the game and use it along with other tactics and tools to move the game forward, they deserve all the fun and awesomeness that comes with it. Have you ever been in a game where both teams are working together with healers, strong slayers and sneaky flanks? That's the most fun I've had with a shooter in a LONG time because of how much strategy and teamwork takes place.
Over time, this community is bound to mature to the point where every game is full of people knowing what they are doing, and it's going to be awesome. The issue that needs to be overcome now is getting the newbies to learn how to play now so they don't leave before they've learned. If the community can do that, this game will have a bright future. If it can't, than this game will have a dangerously low population by next year. I personally will stick around for that, because I want to play this game at a high level no matter the size of the community, but we should still do our best to make the community grow.
I've got to leave for work now, but I'm interested to see what everyone here thinks random people can do to beat camping and make it less popular.