And I'm the exact opposite. I don't want D&D to be the game the represents the game playing fad of the moment, I want D&D to be well, D&D.
Also, I think some people are simply looking for an excuse to reject it and keep playing whatever it is they're already invested in. Truth is, we shouldn't worry about them too much. In some ways, they're lucky. They'll never have to spend money on D&D materials again and can keep playing their nearly-perfect game.

You know what may well be a weird deal-breaker for me:
So, yeah: bring back light as a strictly limited-use resource, especially at low levels!
The funniest thing is I've been going into this whole thing incredibly open-minded. I only had one deal-breaker... and it looks like they've broken the deal. I want 5E to be a NEW D&D, not an old D&D with a little makeup and powder. Unless they are playing their cards close to the vest, we're getting a tricked-out 1970 Impala.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.