What better way to sell expensive hardware?
Now now, lets not forget consoles exist.
I get why they did what they did, because most TVs now days are 4k, but if you know enough about the limits of human vision, it's pretty clear that 4k is a waste for console gaming. It makes much more sense on PC, but even there the biggest noticeable difference is reading text, not playing games.
But the PS4/Xbone/Switch and prior 3D consoles certainly treated 30fps (sometimes less) as a standard in most cases. There's a reason people want to get Bloodborne ported somewhere else, because currently the only way to play it (PS4) is locked at 30fps.