"The legalese opens users to new abuses. That is new, is it not?"
No. If you view it from the legal point of view the old ToS didn't cover what was already happening, opening up Mozilla to potential litigation. As I wrote in the other reply, if you work in legal it's extremely problematic if that has a tiny tiny tiny risk of happening - it's much better to be broad in the ToS.
Technologists are usually the worst at having opinions on law. The only reason I consider myself to have more than average is because of the amount of work I did together with (a very competent) Legal department.
Case in point: 99.9% of all outcry regarding patents have nothing to do with what the patent is actually about.