Because you can't ban HedgeFX if there are still numerous other cases, where the evidence is completely clear, that these Accounts committed Plagiarism. If you ban HedgeFX now but don't ban the open cases of first offener Accounts, that's completely inconsistent.
The forum has always been inconsistent in that regard, this wouldn't be a first. It took us (the Croatian board) 2 years to successfully appeal a ban for one of our quality members. On the other hand, other users who committed the same mistakes got reinstated quickly or weren't bad at all. I am guessing knowing the right admin or having contact with them over whatever social media they use can speed things up.