So who do you expect will donate 100K or a million dollars?

In practice, no one, but that is the threat of destabilizing SBD which was the motivation for banning STEEM donations. I had to address it to make the argument that even that hypothetical case is not a threat to the blockchain. That it is unlikely to occur in practice arguably makes it even less of a threat, but in any case, I don't think that it is a serious concern either way.