Watching diving worse than Barcelona's would probably infuriate me, but if I can get to watch an El Salvador league match (Not sure where to find that) then I shall.
El Salvadoran league matches will be tricky (maybe rojadirecta or myp2p), though you can check out CONCACAF Champions League (on both those sites). I once saw a match of an El Salvadoran team against the Columbus Crew and it was the worst game in any sport I've ever seen. The players and coaches on both teams ended up fighting. They have absolutely no concept of sportsmanship. Their national team is terrible too, and if they are up by a goal they will waste 15 minutes with "injuries."
An alternative would be to watch an important league game in Argentina or Brazil, or perhaps the Copa Libertadores. It's pretty out of control.
As someone who watches them consistently, honestly Barca is not that bad. Busquets and Pedro definitely have their fair share of moments. Alves dives sometimes, but no more than your typical Brazilian. And Villa has the occasional dive. But few even complained about them before the Real Madrid series. I agree they were terrible, but honestly it has a lot to do with the context. That's what you're going to get if you play two teams that hate each other a bunch of times in a row. Especially when one team plays with completely negative tactics.
I've always hated diving, but much less so because I've become a bit desensitized to it after watching so much South American football. It is an art, after all. Mascherano's dive was perfect because it stopped a completely legitimate goal and was hard to pull off. It was obvious from a TV angle that it was a legitimate goal, but from the ref's angle it was trickier, and he did a very good job of selling it. I don't like diving but IMO boring tactical football is much worse. That's why I'll watch diving Argentines and Brazilians over the tough guys at Stoke.