Assuming for a moment that the claims are true - there will still be people who will claim that a reviewer demanding cash (and an equity stake, ffs) in exchange for a favourable review is "just business".
I'm looking forward to seeing exactly who rallies to such a position, and their arguments (as opposed to assertions) for doing so...
I'm not one to listen to reviewers. If I like the look of something and it's within my price range I'll buy it just like anything in life. If it turns out to be rubbish then that's my fault. In my eyes if a reviewer is given something to review then that should be the payment. Use it, review it, keep it. Simple.