"Controversial/sensitive subjects" can mean absolutely anything. It looks like YouTube is trying to control what people can and cannot talk about. Assuming this is true, soon anybody who tries to upload a video to YouTube will be subject to these rules eventually. Only time will tell though.
Why are they mad? Nobody is censoring them or shutting them down. They can still sit in front of a camera and rant about stuff on Youtube, right? Or do they feel entitled to the support from ad companies?
Then get a job instead of feeling entitled to ad companies supporting you ranting in front of a camera?
Nobody is being censored. Nobody is being shut down. Videos are still up. They still have the right to express themselves on the Youtube platform, but that shouldn't take away a company's right to choose whether they want to associate their products with a Youtuber's content.
this isn't censorship... the videos aren't being removed, they're just not making money from the particularly vulgar clickbait videos anymore they're still there, just not generating ad revenue