I totally get what you're saying. Though wasn't similar things said about DirectX11? How long has that been out? and are we seeing all games releasing DX11 versions yet? That is a legitimate question as I don't have the numbers for that, but are we seeing PC games releasing with DX11 support across the board? I think if you haven't seen devs fully 100% accept that yet, then expecting a UE4, that doesn't down scale some what, seems really risky. Maybe I'm wrong, we'll see in time.
Its like you mentioned that UE3 on the iOS platforms has a lot of features turned off, I think you'd be able to see the same for an UE4, but again we'll see.
There are quite a few games that are still DX9 only, but I think that actually fits with what I mean.
When the 360 and PS3 came out, a lot of games released with requirements way above what most people had on PC. We even had mods like OldBlivion and BioShock Shader Model 2.0 to try and make 2006/2007 console games run on the average hardware that PC gamers used.
However, now that we're late in the generation, developers are almost universally still designing games for those consoles, so the requirements to run PC games are quite low as developers don't actually care about expanding for the capabilities of the platform.
Following this trend though, I would expect next-gen games to run like garbage on most people's PC hardware when the consoles first come out, and then four years later be quite lax relative to where the average core PC gamer's hardware has moved to, and then by the end of the generation, seem ancient again.
I mean, even with a game like CoD we're only seeing around 2-3 million copies sold on PC, and a ton of games sell in the six digit range on the platform. It's good money, but when we're talking about 2-25+ million copy hit games, it's an audience that developers are able to jerk around with.
That said, PC gamers often hail games with high PC requirements. Battlefield 3 has some of the most strict minimum hardware requirements of a modern game, but it is what is referred to as a great PC port and sold very well on the platform.
Now, if we were making SimCity, obviously we want something with much lower requirements, but that's not something that's going to be a next-gen console game.