I know several very good professional photographers who's turn-around time is terrible. Month....not weeks.
The problem is that most wedding/portrait photographers are small businesses. They do most of the work themselves...and when they are busy shooting, they don't have a lot of time to spend editing. That's probably a good problem to have because being behind the camera is where you make money, and sitting in front of the computer isn't. But at some point, it's going to bite you (them) in the butt.
I was attending a seminar on the business of photography and the speaker was talking about the time issues with photographers. He said that as the business owner and (main) photographer, you time should be worth $50-$100 per hour. So if you're spending most of your time in front of the computer, when you could be behind the camera, you are loosing money. The solution is to outsource anything that isn't worth your time. So if you can hire someone to do the post processing, and pay them $15-$25/hr, you are still going to be ahead. Not to mention that you'll have more time to yourself (family etc.)
I've seen several photographers work themselves into this situation. They work really hard to get their business going. They book a whole bunch of wedding/portraits and everything is great. But when the busy season hits...they get swamped with work and the backlog of editing in the 'to do' pile, keeps getting bigger and bigger until it looks like they're never catch up. This typically makes them stressed out and burned out...which doesn't help for getting things done any faster. This drives many of them out of business altogether, others have to limit how many jobs they take for the next season etc.
So, my point is...many photographers have a fairly long turn-around time, and if you can get it done in a couple weeks, that is usually going to be good enough for most clients. Of course, I'm assuming that we're talking about weddings & portraits. If we are talking about commercial/editorial photography, turn around time may have to be hours, not days or weeks.