YouTube does not employ creators; creators are utilizing YouTube's free service in order to broadcast their own content. Google demonetizes videos in order to be more appealing to advertisers , ultimately the problem these creators have is that advertisers are not willing to pay for their content. YouTube only makes money when the content creator does, so naturally they'd be happy to monetize anything they could.
Youtube doesn't create content. They utilize content provided to google for free by creators to drive traffic to their website. Google monetizes videos in order to be more appealing to content creators. The problem these creators have is that advertisers, corporations, competitors, and copyright trolls are easily able to game google's automated systems to get channels demonetized and content censored. It doesn't matter to youtube if a channel is demonetized because it still drives traffic to their website, it still provides google with a trove of user data (both from the person visiting youtube and the content creator's own content and usage of the site) and they will happily autoplay/suggest videos full of ads to get visitors away from the demonetized channels.
aggressive demonetization/censoring is far less expensive for google than properly moderating content, and it lets them show they are "doing something" which keeps advertisers happy and the copyright cartels at bay.