If everything operated on a donation principle, it'd be a new shade of socialism and it'd be glorious. See: Americans using GoFundMe to pay for their medical bills, crowdfunded games, politics-related petitions et cetera.
And you guys are absolutely right about Patreon and things like that, it's a great and not at all objectionable way to make some money on the side.
Donations is fine. I've got nothing aginst donations. Just keep in mind that it's only a donation if it
A: is voluntary
B: offers no gifts, no special CC, or isn't otherwise a pay item in disguise.
If you have to donate to get a special item, it's a pay item. Don't get tricked into tinking otherwise. There's no difference between "donate to get item X" and "pay to get item X".
If people use sites like Patreon to offer "special downloads" not downloadable for free (maybe unless it's available after a certain time), it's essentially a version of a pay site.