Let's call this a hypothesis.

I hypothesize that every person who identifies as a Furry has at some point in their life felt inadequate. Someone has told them, through words or action, that they are not good enough, that they are deficient in some way. And, for however brief a moment, that person believed it. That's why people try to make a 'better' version of themselves, their fursona. To try to silence the doubts that these comments plant.

And I think that is why the Furry Community is one of the kindest, most accepting groups in the world. Every person in this community has felt that inadequacy, and no one wants others to feel that. That's why they accept everyone. Everyone gets a chance to be their better selves. Everyone gets the support to be themselves. And it's also why there are few more fervent defenders of the wronged than Furries. They've felt the ridicule and they won't let others suffer from it if they can help it. Furries are accepting of everybody...except dicks. If you're a dick, and you try to be dickish around Furries, you better have an escape route prepped, because you will not survive the wrath of the Community.