I can see why the video would have been contentious - the general impression given was that the IP that ARM (the company) inherited wasn't that great, which doe

I can see why the video would have been contentious - the general impression given was that the IP that ARM (the company) inherited wasn't that great, which does't seem entirely fair. Also RISC OS was a desktop OS and Thumb etc was all about getting into mobile devices and so in effect abandoning that legacy. In fairness though without Thumb ARM would be unlikely to have reached its market position today so credit due I think to all those who contributed to the evolution of the architecture (including the team that developed A64).