Why? Amazon isn't required to carry every product everyone on HN deems important. McDonald's isn't required to carry Pepsi products because someone likes Mountain Dew.
To your follow up: some kind of anti-competitive explanation for why Amazon shouldn't be allow to do this isn't really going to hold any water in this case.
This. To be honest, I think the customer confusion they say is coming from the fact that chromecast was a Prime product and therefore had a Prime logo next to it while buying. That could confuse some buyers.
But the sane thing to do would be to remove these players from Prime shipping, not axe them altogether.
Their explanation is just insulting.