Why not provide a generally accepted framework (orcs, drow, and ogres are bad, evil creatures) that the majority of DMs and players are more comfortable with as the base?
Are they? Whats left of the once large D&D fanbase likely is. Everyone else who wants complex games has already left.
And if 5E wants to regain those players (stated goal) then it shouldn't continue down the line of 4E (simple, one dimensional monsters)
If you want to tailor your campaign so that all ogres are really just big, lovable creatures with anger management issues (aka, Shrek), you can do that. Why does that take away from the game if it is not core? It speaks to a lack of imagination if you need core to provide your monster / race motivations.
I would rather say the inability of you to simply leave out stuff which is in the books is the problem here.
Why should someone choose a game system where he has to do everything himself because the system is primarily made for simple hack&slash games instead of a system which already does some work for him?
Because its D&D? Since 4E and Pathfinder the brand bonus isn't enough any more.
That has nothing to do with a lack of imagination, but with time management.
And here is another question for you - what is a more dangerous path for WOTC to traverse: using generally accepted fantasy ideals and frameworks or going out on a limb and pursuing a specific agenda for a core race / monster that may or may not sit well with the majority of gamers?
Whats more dangerous? Continuing with 4E style of design which was a big failure and has driven away large parts of its customers thereby getting more and more eclipsed by video games which provide better H&S and are catching up on the social component, or using a different kind of design which sets it apart from Video games?