I think that we got so used to being unaffected by very extreme images of both sexual and violent nature, that it takes a lot to shock people those days. The shock factor is one of the most thought after effect in advertising - I mean, you remeber this, and not only that you are spreading the ad now in this public forum. That's not only free advertising, but the best free advertising there is cause I gave this image much more attention here then I would have if it was just a banner or an ad.
So, since plain girl in a bikini doesn't really do it as far as shock factor goes, you have to turn to more extreme measures like a guy fondling a monkey.
Also, condoms are hard to sale, it's still an embarrassing topic, you can either choose the medical - scare approach or go with humor, those are the two main methods advertising had worked for condoms in the past.
Honestly, I don't think it's advocate animal cruelty, because it's obviously a cultural reference ad done in humor. I think it's childish and rather stupid, totally don't make me want to get those (plus banana flavor?! yuck!) I think a big part of this campaign was made trying to get people to write angry letters to news papers and get upset about this online for the free ad space.