I think my main issue is the shift in focus away from a transaction (people paying for a product or service) to reducing people to simply being sources of money.
Also, the idea that fans or admirers should be converted into people who pay you money. My concept of a service like Patreon is that it's a way for people to give you money if they (independently) want to, rather than being pushed or cajoled to do so.
Making good content consistently is hard work, I personally have no moral qualms about a creator trying to make a living doing it.