Tonight I finally got frustrated enough to look for a way to disable it. I tried searching on things like 'disable TinyMCE' and 'block TinyMCE' - but I just kept finding pages with instructions to web masters on how to incorporate TinyMCE and allowing their users to disable/enable it. I thought about trying to put something in userContent.css, but that was too much work.
So keep it in mind if you run into things like this - AdBlock Plus can block any content from loading, you just need to enter the right URL pattern. It is useful for more than ad blocking. :-)