I think a lot of it goes on, but as ScrawnyBob points out, most of it is by below average players. I have seen a lot of deals where two guys sit down at the same table in a cash game, they sit away from each other if possible, then raise raise raise. Anyone between them gets trapped. You call then get raised twice before it comes back to you. If you have a decent/marginal hand you will fold and they take the blinds and a call or two. If you call they usually raise raise raise the flop then the weaker of the two drops out after the turn if one of them has hit. You play tight and you win twice as fast because there are two morons raising into the set that you flopped.
