This is part of marketing. These streamers have audiences that see the game and there are people who may have been on the fence until they saw the stream. They aren't streaming to rub it in your face and HBS isn't giving them access because they are cool guys with popular streams.
This is one of the many ways in which success is accomplished.
You could start your own game stream. You'd have to pay for things yourself until you build up enough audience that game developers partnered with you. Of course that would mean that you would likely have to play games that you had little to no interest in to keep your streams up. You'd also have to use less capslock...
But seriously, this is how the system works and in all, this is a good thing.
Watch out for the Troll