So from what I read you had another forum software before and you changed from the excellent phpbb to the discourse crap. Yeah, well I get it, phpbb can be a bit of a pain to keep updated. InvisionBoard is way better, also XenForo is awesome.
(Speaking as a person with 30 years of experience administering and moderating different platforms)
So I take some pride in using a relevant Internet Persona where I am. This includes avatar, and, when possible and relevant, signature. I have not been able to find where to change my avatar, I know it is possible, since I am a member of other Discourse forums. The avatar you display is not in any way related to my activity here and its been fetched from a wordpress.org gravatar I use occasionally, but do not want to have here. So I changed it, but I would still ask you to grant us more options than the Gravatar contraption. Or is that ability locked behind a post count or activity rank? Not that I care about those.