The demonitization doesn't suck as hard as Youtubers said it would be, I predict, but it's also a bit of a complicated issue. It's basically Youtube now having the right to remove monitization on videos if they deem them unfriendly for advertising, according to certain criteria. The most commonly mentioned problem about them is how vague and broad they are. A lot of famous Youtubers have already had several to many of their videos demonitized which is going to limit how much money they make and staying alive unfortunately costs money. They could "get a real job", but that's a shitty (banned word for monitization) alternative. Making videos for these people is a passion. Working at McDonalds or a local grocery store is something to be ashamed about. But I'm sure a good portion of these people could aim a bit higher than that anyways

Some claim that this is censorship and it's partially true. People can still make videos criticizing others but they have a high likelihood of being considered "harassment" because someone's feelings could get hurt, even if the person avoids calling them a banned word, letting 1 side of an ideology go unchecked because the opposing side can't make their living off of criticizing it anymore. Those Youtubers will have to work "real jobs" to afford to stay alive and lose 40+ hours every week that they could be using for research, video making, and other related stuff. It's basically a stealthy version of censorship

In Youtube's and advertisers' perspectives, this might be a good idea to raise profits. Ad agencies don't want their ads associated with unfriendly things like Leafy's and cringe videos because ads simply aren't effective there. IDK the deeper psychology behind it. By demonitizing ads there, ad agencies will get their ads put only on content that will more likely lead to more sales. All they seem to want is the fat trimmed to save money. Online advertising is unfortunately not very effective because the whole internet is basically a distraction service. By having ads only on videos that are ad friendly, this could lead to ad agencies competing with each other by out bidding each other for more ad space, which would of course help Youtube make their profits

The new policy is probably aimed to motivate Youtubers to make more ad friendly videos. It may help them in the end if they clean up their language, but it also restricts the content they can make. Some Youtubers are entertaining because their style of it is being a cunt and making fun of other cunts (For fun, anyone want to guess which Youtuber I'm referencing? "Cunt" is the hint). Removing their vulgar language would make them less fun to watch. For those who can stay entertaining with the restrictions, this could lead to them getting more money because advertisers will want to bid more on putting ads on their videos

But there are 2 problems to Youtubers complaining so much about this policy that needs to be pointed out. Sponsors pay more than video ads and ad blockers make this policy irrelevant to those viewers individually. For the Youtube sponsorship 1, it unfortunately takes a lot of subscribers for someone to get sponsors. According to Drift0r, they usually don't happen until 100,000 or so. For the other problem, ad blockers are increasing at an exponential rate. More people install them every year. If the pattern continues, in several years, the prevalence rate of non-ad viewed videos will be too great for any monitization, ignoring the new policy, to make much of a deal about (I know Youtube has paid Adblock to white list their site, but IDK if they're still doing that and Adblock is only 1 ad blocker developer)

The new policy is enforced mostly automatically and many big channels have been scanned for videos that aren't ad friendly. I've heard some theorize that it's based on banned words in video descriptions, titles, or tags. I'm not sure if that's true though. There are 9 videos on my channel with the word "Fuck" in the title and none of them have been demonitized. I haven't had this new policy affect me at all. It could be because mine hasn't been scanned yet. This is just my own theory, but video flagging may have an effect on what gets auto demonitized too (Baseless theory). Maybe the scanning only happened on big channels 1st

Full guidelines https://support.google.com/youtube/answer/6162278?hl=en