FurAffinity is to the furry fandom as Facebook is to a lot of more general communities. There are a lot of perfectly legitimate reasons to avoid both websites, but in doing so you end up crippling your ability to be social with a large number of people.

Both websites have a habit of changing policies without warning, enforcing changes retroactively, selective enforcement of policies, and absolutely no recourse for users wronged by a policy decision. When Facebook makes changes to its privacy policy, those changes often result in previously-private information becoming public and users are left scrambling to make it private again, assuming they can even make such a change. FurAffinity has made changes prohibiting certain kinds of content (e.g. cub art) and then deleted all existing content that doesn't conform to the amended policy. Both websites have a habit of completely ignoring user complaints except for a small number of high-profile users, and FA in particular seems to side with someone popular despite overwhelming evidence that they've done something wrong. If a user is told off by an administrator on a power trip, the only thing a user can do is post a public complaint about it that is unlikely to ever be seen by the overwhelming majority of users, assuming that post doesn't get them banned for daring to speak the truth on a matter that ownership finds unflattering.

However, in choosing to avoid the site at all costs, a potential user severely impairs their ability to be social. A large number of events are posted exclusively to FurAffinity or Facebook, with an expectation that all people interested in attending will RSVP via those services. Most people who are active on one of those sites are not nearly as active anywhere else. People who post on FA rarely cross-post to SoFurry, Weasyl, etc. and those active on Facebook similarly don't post on Google+, Twitter, or other social networks. There are plenty of promotions (such as giveaways) that require interacting and resharing content via that service. And of course, there's the simple fact that more people use FurAffinity or Facebook than use all meaningful competitors combined, so there's a huge audience you can't reach by avoiding the services.

So what's someone to do who doesn't like the sites? It seems like the only viable option is to create an account and use it anyway, while simultaneously encouraging people to use other services more extensively. To that end I've created an FA account under the name  Sovrim that reflects my change of primary character from a few months ago. I have no intention of posting any of my own content to FurAffinity (aside from perhaps a teaser and a link to my SoFurry page to read it in full), but boycotting a website and missing out on a large number of possible social events and freebies seems like a frustratingly self-destructive approach. Though I certainly hope that alternative websites get the attention they deserve in time, for now it seems that the currently-dominant players in this space will remain difficult to function without.