As always!

Eh.

a) It's their site, I can hardly fault them for not wanting to sell something that is actively damaging to them.

b) It's in the customer's best interest for rankings to accurately reflect popularity of products. I have no sympathy for an asshole who wants to instruct other assholes in how to clutter my search results with their crap.

c) Removing it is certainly a far more honest solution than artificially downgrading its ranking.

d) Again, their site. Bars have the right to kick out patrons who are being dicks; there's no reason Amazon shouldn't kick out authors who are being dicks.

Someone at this company has a really small penis.