Why haven't consoles multiplayer combined?

tl;dr? Transistor was great.

I'm playing that on PS4 at the moment, and am thoroughly enjoying it. I've found the combat system a bit hard to get into though - I don't think I've played any two consecutive fights with the same loadout. I'm sure I'll settle on my winning formula on a second play through, but I'm nearing the end and I'm still trying things out (which, I guess, isn't necessarily a bad thing, but it can be frustrating).

Anyone try the Dark Souls series? I've been hooked for more than a year now, and Bloodborne comes out in less than a month.