I'm a furry, and I do enjoy R34 art. I can tell you that many people greatly participated in this fandom are also part of the furry fandom as well, and without us it just wouldn't be the same. For instance our national brony comunity was built by a bunch of furries who really liked the show. More people joined in over time and now we have over 1000 members. That's almost 50 times more than the original group. I understand that some find this distasteful but don't judge people on this single preference please. I know a lot of furries and a few bronies, even a few furrybronies and most of those people have completely normal interests, jobs and relationships. There are a few douche bags and creeps but let's be honest... most social groups have those.
I wouldn't call us the "dark side"... if you want to see dark take a visit to 4chan section and grimdark part of the fandom or perhaps the fluffy pony gore. Perhaps its just my biology studies speaking I wouldn't want to see this part of the fandom leave as well. It creates diversity, and that is important in an environment that has any ambitions for longer tern survival.