Well games are expensive to make and publishers/investors generally will be cautious about things that are different.
There’s a team working on a UE4 MMO that looks pretty cool (can’t remember the name -_-), but some of them were working on Rift, and it seems like Rift was meant to be something quite different from what it ended up as.
I’m pretty **** sure developers everywhere have all kinds of ideas for games they’d like to make, but the money has to come from somewhere.