Well, they wouldn't. Going to the PC would be truly last resort, I feel. It'd be good news for me, since I own a PC and do not own a Wii U, but they give literally zero fucks about me. And too right.
Whether it would improve their profit margin? Who knows. The games Nintendo makes don't lend themselves super well to the PC. 3D platformers and local multiplayer-focussed games aren't exactly the biggest hitters on Steam. Furthermore, Nintendo is rather paranoid when it comes to piracy. There's a good chance they'd use restrictive DRM, or would avoid Steam entirely in lieu of their own store. So there's that. They do make high quality games, though. And there's a large PC market out there, so it's difficult to say.
But yeah, it would be a pretty big sign that Nintendo had lost faith in their own product, and they just wouldn't do it.
Whether it would improve their profit margin? Who knows. The games Nintendo makes don't lend themselves super well to the PC. 3D platformers and local multiplayer-focussed games aren't exactly the biggest hitters on Steam. Furthermore, Nintendo is rather paranoid when it comes to piracy. There's a good chance they'd use restrictive DRM, or would avoid Steam entirely in lieu of their own store. So there's that. They do make high quality games, though. And there's a large PC market out there, so it's difficult to say.
But yeah, it would be a pretty big sign that Nintendo had lost faith in their own product, and they just wouldn't do it.