Well I think Amazon just played the tit for tat card here. Historically, Google took the first slab by banning Amazon from it's app store: http://techcrunch.com/2014/12/11/google-removes-amazons-app-...
No wonder Amazon is now reciprocating by explicitly disallowing chromecast devices on its own site.
tl;dr; Google ain't a saint/good citizen either. No one is.