No evidence is presented for this scary hypothesis. There isn't much I would doubt, but to corrupt doctors like this would be pretty hard.

Cuomo kept doctors out of the loop and just sent the infected into nursing homes. Doctors are kept out of the loop in giving shots -- they give them in CVS and parking lots, far from any competent medical advice. There are many many doctors who could not be corrupted into killing people, and quite a few who avoid recommending the shots, although they probably get in trouble if they openly discourage the shots.

The FDA has broadened their approval of Regeneron convalescent plasma (this is the shot Trump actually had, not one of the vaxes) but were careful to make sure it's only available in hospitals. I believe that's quite a safe product and probably very helpful for moderate or severe Covid. The FDA are not big fans of independent self-care. Also I remember it's slow to manufacture, so the supply could be limited.