Getting accounting correct in this kind of situation is just very hard, and sometimes people get it wrong even with due diligence and advice from trained professionals in the field.

Saying this is "supporting bad practices" when they are addressing the problems with their set up is IMHO disingenuous.

(This kind of problem also illustrates why Mozilla is set up the way it is, with a Foundation and a Corporation. Tax Law doesn't always deal well with doing both in the same org.)