The term “ad hominem” gets casually thrown around quite a bit in these parts, but boy howdy this is the literal textbook case of it. Plummer’s not one of the good guys, noted. Is he factually wrong?
The stuff he claims on his videos are at best misleading at worst outright lies. Like his recent claim that he made the vertical text in Windows start menu render in real time instead of a bitmap. Except every version of Windows (released/beta/unreleased or even the various source code leaks) that had that type of start menu used a bitmap.