IMHO that’s probably the best reason for having the User Card vs. “always there”
If one is not interested in that information it is nothing but distracting visual noise and clutter.
If someone is interested, a simple click is all it takes.
That said, the post.hbs template has a plugin-outlet
{{plugin-outlet "poster-avatar-bottom"}}
which is located beneath the avatar of each post
So using a plugin to display stuff there should be easy enough if you really wanted it.