It is not indeed, but again, so can be said the same about keeping people playing the game
Whether you like it or not, the streamer community together with the website and youtube community is helping WoW by keeping it interesting for people.
These communties are not saying, that Blizzard should use money just so that they can keep their jobs and income. They are saying, that Blizzard should increase the amount of stuff they can use for entertainment, so that they can keep their communties going, which helps keep the WoW population happy. You would be surprised on how many people are kept in the game, because they are also satisfied with other entertainment while they are not playing the game.
This is something many other companies have acknowledged, which is why they fight and pay streamers to play their games. Seeing other people enjoy a game or do content which seems enjoyable makes people want to have the same experience.