Look at the participation-sorted tab of users (same order on responsive and mobile sites on my phone):
John Omielan only has 5 actions, with no posts or reputation gains other than the association bonus:
However, Alex, a very prominent user, has hundreds more actions:
Is this a bug, or is there some extremely convoluted logic here?
Note to John: I’m not trying to single you out, this is just a weird behavior of the site.