I don't see why's it such a big deal letting people have negative opinions of something. Perhaps there's folks out there who knew some bad examples of furs (inappropriate conversation, hygiene/appearance, something more private) who have a good personal reason for disliking them, even if those reasons don't apply to most of the fandom.
As long as someone isn't going out of their way to personally attack furs and make their life worse, people can think what they want to. Someone stumbling across a few anti-furs on a site might upset that person, but it doesn't mean we need to swarm in and spread pamphlets on how amazing furs are.
~~~OPINIONS BELOW~~~
Being involved in the fandom is very much not like Justin Bieber or Twilight. Those examples are too strict. They're one entity, not even a genre or fandom (Twilight doesn't have enough of a mythos or history built up to denote a fandom, IMO). Most people dislike them for one or two reasons: either they personally experienced and disliked it, or they can't stand how the fans act. I don't know many people who get involved in the furry fandom because of fad status. What is there really to gain from associating with furs, in terms of popularity? I mean, you can make friends (always nice), but I wouldn't say furs are "in style". The closest thing I've seen to latching onto furry trends are places like Hot Topic and online shops selling hats with ears, or those fluffy animal-style caps with the long droopy parts on the sides.