There had been a bug in the past too where a member can already have an avatar, it would be great to have such account.
Avatars were banned for a long time because of the possibility of injecting dodginess via images somehow. Accounts that already had them could keep them which made them attractive to some.
I praise the lord that this site doesn't allow gifs and images in signatures and avatars. So many forums are unbearable because of them.
But some people do have gifs - look at Phinnaeus Gage/aka bruno's account (Sorry no link handy on mobile).