Bond being gritty has nothing to do with why I do or do not want Q as a character.
My key issue with the character returning is that Desmond Llewellyn is dead, and hence the point of featuring the character is now gone. Llewellyn was Q, and it was nice to see him show up in each film... a reminder that this series has a history. But now he's passed away, and the character doesn't serve that function as a nostalgic connector anymore.
But Q Branch isn't important. It doesn't add that much fun (beyond a few groan-worthy lines of dialogue and some sight gags). And now, with gadgets taking a back seat, it's even more natural that we don't get Q Branch appearances.
Now, this isn't to say that I'd be entirely opposed to Q returning in one form or another. But I'd go back to Fleming. Call him Major Boothroyd of Q Branch, not "Q." And make him the armourer, not gadget-meister. Also, a change of personality is in order. Llewellyn did the grumpy guy, and nobody can do that better... so how about a man who lives vicariously through Bond? And make him in his 40s or 50s, as HR-PUFF&STUFF suggests.
Really? I don't think so. Most people still admit that the early Connery days were classic films of great ingenuity. But it's hardly wrong to start criticizing where the franchise went after 1969.
The franchise moved into autopilot mode, where the films became more of a set of ingredients than actual stories, and while there are exceptions, but for various reasons they weren't quite up to the high standard of years past, and even they were tied back by formula (Q's appearance in LICENCE TO KILL feels wholly inappropriate, given what the film is going for).
This is not to say the films aren't fun. I enjoy MOONRAKER and OCTOPUSSY a lot. But that doesn't mean they were great, or that what we got in CASINO ROYALE wasn't an improvement. It's possible to say, "I enjoyed what came before, but CASINO ROYALE was a step forward."