Steam users or console owners have spent time, money or both just to have the equipment to play games. I'm guessing that the same market that buys consoles buys smartphones, so they may be more likely to buy good phone games. But maybe not! I mean, they have a console at home so if a game they want is cross platform maybe they prefer to play it on that?
The gaming experience is also hugely different. They are converging, but there are still so many differences. That blazing fast new processor doesn't do much for controls, screen size, battery life, multiplayer - all of these are things that stop phones from competing with consoles directly. My guess is this is a reason that the top games are time wasters.
Compare the most popular free games on Steam and consoles with mobile devices. Off the top of my head, Candy Crush Saga and multiple free Angry Birds titles have over 100m downloads on Google Play alone.
I would say mobile games are viewed as more disposible than PC or Console games.
Developers can pull a game from the Android or iOS markets at any time and unless you somehow made a backup, you'll never get to play it again if you happened to reset your device or get a new one. With steam though, my game library stays there, even if the developer no longer sells the game on Steam (happened with the Wolfenstein game that came out a few years ago). Also, many mobile games also depend on server side resources and won't function without them.
