I hate to use this example, but MB is a good example of Patreon/SS done correctly. Game is free, give money to support, and your support is rewarded based on how much you choose to give. Give lots, you get it earlier than everyone else.
There are some others too, Leaving DNA would be an example I can think of... He takes Patreon subs for consistent support, but he sells on Itch for those that just want to buy the content. It still ends up here, but later.
Patreon is not a method of selling stuff, whether it be a product, service, or anything else. It is a donation platform, that some creators use for exclusive content.
That is the thing, as my example above, it is a promise of early release, or access to the dev, or their discord. It could be exclusive renders, or a Q&A, or it could be absolutely nothing.
And the entire purpose to Patreon is because it is meant to support creators on a steady basis. Quid pro quo is, you give me (the creator) money, and I'll keep putting out content.
BD has absolutely lied, and I'm sure there are tons of other devs that have burned their subs.... But that's the risk you take when you're donating money to people. That bum on the corner may take the $10 you gave him to go buy a hot meal... or he might just shoot it up his arm. That's the gamble.
I'm not disagreeing that Patreon is being abused, in this case by BD. But that doesn't change what the purpose of Patreon is, which is monthly donations to creators, to keep them creating.