Generally, profiles have fairly wide latitude in what is posted on them as long as the account isn’t solely intended to drive profit/creating spammy content on iNat. If an account is otherwise posting non-spam content on iNaturalist, this is probably ok for profile text. Users also post to personal websites, link to their books/publications which may be purchased, and link to other online accounts (like Youtube channels) which could be monetized on their profiles, which is ok.
That said, the forum isn’t for discussing/calling out specific instances of questionable or bad behavior on iNaturalist itself. I’ve left this topic listed for now as it is fairly general. However, if folks wish to raise questions about specific users on iNaturalist, the appropriate action is to raise a flag there for curators or staff to assess and take action as needed.