You can make ice cream. Walmart could stop selling ice cream completely and it'd be just an inconvenience (and you'd eat better ice cream).

Removal of an app from Google play store isn't a big deal, any android user can download the apk.

Removal of an app from the Apple store is a bigger deal. I believe you need a jailbroken phone to install apps from other sources. Right there, nearly half your app's users are gone. But there's still the internet, they don't need an app.

Now the servers are a bigger deal, migrating can possibly be a real pain in the ass. And it's almost like a utility these days, you wouldn't expect to have your power turned off for your political ideology, or if you believed in something fantastical like big foot, UFOs, or Trump winning the election.

If this was Joe's Server Co. down the street nobody would blink if Joe didn't want to put up with hosting a controversial site. Amazon is big though, they aren't Joe down the street. Again, I keep thinking of the utility I mentioned.

I guess it depends what you think Amazon's role and responsibility are.