I do agree with what you are saying and I too, feel it's not good at all to put all my eggs in that one basket.
In fact, would there have been good alternatives I would have gladly spread those eggs
That being said, I don't believe it's just a matter of "posting a download link and a few previews", considering the time I currently put into my Patreon page. Also, I'm a bit careful about just signing up with any platform as we are dealing with large sums of money here, both my supporters and my own, which makes me rather err on the side of caution.
On the other hand, reading your post, does make me think that maybe I'm seeing more obstacles, than there really are.
It's just that the whole Patreon thing has had me on edge for quite a while.
Thanks for the food for thought!