It's hardly the end of the world, getting an irritating bid is it? Unless they're sending multiple bids. I suspect SPs get dozens of improbable requests every day.
Not the end of the world, no - but still irritating when it locks your booking request so you can't then change it (I know Steely has said in this thread that it is possible, personally I have never been able to do that after someone has bid on it, even after deleting that bid - I get a message saying "You cannot change this reverse booking now someone has expressed an interest in it".).
Plus it can be a way for someone to send an unpleasant message to you with no way to stop it, unlike blocking emails. I had this happen from an SP who I reviewed neutrally on this site. 18 months later she replied to an RB just to have a go at me about that (although not disputing any of the things I had said).