Affordability, comfort and convenience. Anyone who argues over how PC gaming is better doesn't understand the sheer simplicity of just sitting down, turning on your console and gaming (unless they do both).
A guy in my office was ranting about stuff a little while ago (I over hear conversations) and he was wondering why anyone would want a console and game on it. But a high end PC is not only expensive but has to sit somewhere, isn't attached to your main TV. If I got involved in the conversation I'd ask him what car he has? When he tells me he doesn't have a Audi R8 and I ask him why, my point is made. People prefer one thing over another, the fact console gaming is just far simpler helps, whether it's the control scheme, setup or whatever.