Why alienate such a large segment of users after pouring so much money into their technology? The web is getting weirder.
If a company invests in multiple markets, they should be prepared to do well in some markets and badly in others. Bing isn't as good as Google. Android isn't as well-designed as Metro. Yes, Android stole Apple's market, and, yes, Apple stole someone else's market. The large technology companies are deadlocked on multiple fronts. That fuels fierce competition and inspires excellence and choice. However, companies should accept they just aren't the best at everything. Let us make our own choices based on what's best for us.
I think you are attributing to malice what is probably just laziness. It is fairly common for modern websites to drop the ball on support of some browser or other. I doubt Microsoft as a corporation made a deliberate decision to support IE and Firefox but not Chrome or Safari or Opera or whatever.
It's one thing to not test a site in a particular browser and to just put up an unobtrusive warning saying that some things might not work perfectly. It's quite another to actively block access based on the user agent string.
"Android stole Apple's market" eh? Must be why Apple is losing money hand over fist. Apple fans can be annoying but fandroids are often detached from reality.
If a company invests in multiple markets, they should be prepared to do well in some markets and badly in others. Bing isn't as good as Google. Android isn't as well-designed as Metro. Yes, Android stole Apple's market, and, yes, Apple stole someone else's market. The large technology companies are deadlocked on multiple fronts. That fuels fierce competition and inspires excellence and choice. However, companies should accept they just aren't the best at everything. Let us make our own choices based on what's best for us.