That's SteamSpy for you. Like PayDay 2 selling more than 4 million. Pleaze.

Probably SteamSpy somehow inflates numbers, but they're high nevertheless. Even if those numbers overtrack games on Steam, Steam itself is just a part of PC gaming.
Game devs surely have more reliable estimates available and they still develop for PC, and yesterday devs announced a complete edition of Far Cry 4 that at least initially will be exclusive for PS4 and PC http://www.vgchartz.com/article/258960/far-cry-4-complete-edition-coming-to-ps4-and-pc/

If PC made developers as much money as consoles did they wouldn't prioritize consoles. It's as simple as that. I dislike that since I prefer buying games on my PC, but that's how it is. That being said, Steam keeps getting bigger and bigger so things might change in the future.

I don't think it;s as black and white as you;re making it out to be and also what about PC exclusive games and devs?, please don't just sum it up with a few words that come off the top of your ehad, I want more data against this sort of belief than simply stating an opinion as a form of fact.