My number 1 reason for playing Domination is the with 80% certainty, I know where the enemy is going to spawn... not to spawn trap them, but to avoid having them spawn right on top of me. The spawn system in MW2 is absolutely broken. Even in domination there is no gaurantee. That's why I said 80%.
BTW, jumping on flags is not the only way to be a team player. I don't need the points to rank up, so I will assist others while they are capping. You can also defend flag(s). How I play depends on my team. If they are aggressive and capping flags, I will tend to hang back and cover them. If they are camping, I'll throw on marathon and lightweight and go get the flag myself myself.