The thing is though at least YouTube still continuously improves and actually deserves to be on top of the marketshare. Twitch still uses a crappy flash player, mutes entire VODs, and more.
YouTube has an HTML5 option (more prominent now and quite nice actually), doesn't mute videos, etc. There are problems with it of course, such as ContentID, but this hasn't been nearly as rampant as Twitch's muting.
If Hitbox got as big as Twitch, it would be forced to do the same kind of thing