Google wants their own protocol to succeed, Mozilla wants a different video codec to succeed[1], Microsoft probably wants to own both. It's very easy to cache HLS, which makes distributing high definition to a large number of people much cheaper. Is Apple supposed to spend more money on lower quality steaming just because their competitors don't want to play nicely?
VLC is capable of playing HLS if you can get it the correct URL. Some other browsers can play it, but the web has an unfortunately long history of browser detection.