I've managed to find a way to rush and be unpredictable... It's called dexterity, and it's effing genius. I've had most of my rushing success (I only rush with the R870 or the B-knife, because I like a challenge) to dexterity because I just bounce to their window and blast 'em.
It also doesn't help that these people that spawn, rush, die...... are probably little kids that just learned to wipe.
Not all SMG rushers are terrible. If they are constantly disrupting the enemy, calling in scorestreaks, and capturing/protecting objectives, despite running around the map like a madman, then you might just need to watch your back a little better.
My team does piss me off more often than the enemy. But what pisses me off is not the SMG rushers, it's the people in the objective games who don't even bother going for the objectives... like you said, I'll be the only one trying to capture B. And what's crazy is that sometimes I get it all by myself. I can't count the number of times I would have gotten it if one more person would have spent just a few seconds helping me out.
The SMG rushers are more often than not the only ones who help me capture objectives. ARs, LMGs, snipers... I'd be really lucky to see them going for an objective. Sometimes they'll provide backup though.
Don't get me wrong, SMG rushers do tick me off sometimes... usually on Hijacked, when I've barely made it to the middle of the map and already getting shot from respawns behind me.
Yes, it is annoying but the only time that it really bothers me is when I'm trying to use a longer range weapon and basically don't have the mobility to deal with the spawns flipping non-stop. So not only watch your own back but be sure to pack a good secondary so that you can compete with the guys that are going to pop up behind you.
I play a lot of KC and this is just as bad on a non objective based game. I can't move 3 feet without the spawns flipping. There's just too many people bouncing from one of the map to the other.
I actually stopped playing one night because I couldn't get away from Hijacked where it's the worst, my killcams would actually show me and the enemy spawning together side by side. How the Hell is anyone suppose to effectively play the game when this sh*t is happening