There's a philosophical split in the photo world. And it becomes more and more polarized as digital workflows become completely ingrained and more powerful. And that's the argument about the need to get the shot "in camera". Basically take pictures that don't need further processing in PhotoShop.
I'm all for getting the picture in camera if you can, but it's certainly not the only factor. For plenty of pictures, time might be a constraint, or it might be impossible to bring or setup the necessary lighting. Maybe you don't want to lose the connection with the subject while you riddle for 15 minutes trying to get everything perfect. There are plenty of reasons why you can't.
All of this said, for certain kinds of photographers, getting the pictures right when you click the shutter makes perfect sense. Event and wedding photographers for instance, or photojournalists. The closer you get it in camera, the less time you have to spend after the fact, therefore the more money you make. But for me, I'm generally trying to get just a handful of final images from my shoots and I don't mind spending time to get them perfect in my mind. In fact I like the post-production process. And maybe that's it, some people just don't enjoy that half. They see it as work where the shooting part isn't.
I've recently heard arguments which put make this about the craft of photography. Essentially, that if you can't get the picture in camera, then you're not good enough. Personally I think this is something of a red herring. This is an argument I often hear from, shall we say, more senior members of the photographic world. It often goes along with a, "In my day..." kind of speech. The ability to editing things so fast in a computer makes it too easy in their eyes. The thing is, they used film mostly. It's not like they were using collodion glass plates and albumen prints. How many of them processed their own film and made their own prints? Back then manipulation of the image was by use of different developers or more contrasty papers. People use the tools they have available in their time, and change is hard on everybody. I for instance don't really look forward to the fad of photographers shooting video footage. I like shooting stills. Maybe that makes me a Luddite.
I couldn't have gotten a number of my Drabbles series of picture without extensive post work. Sure, some were pretty much as they were in the camera, but a number of them took many hours of work. Just because PhotoShop is powerful doesn't mean that it's easy. Sure, I can teach my mom to remove a zit with the healing brush, but could she put together seamless composites? A power saw is fast and relatively easy to use, but that doesn't make us all Norm Abram. There is just as much craft in retouching as there is in camera work. Why do you think the best in the business make a thousand bucks an hour? And I think the bias towards the latter being a 'better' craft is a prejudice that should be given up. Both have their place and the space between them is a continuum. I consider myself well skilled in the 'craft' of photography. Of working with light and exposure and with what I'm given in a particular situation. In fact, I don't generally do much if anything to pictures I shoot on film. But I also understand the advantages of being able to take those pictures to the next level in post. There is art in each, and in both together. To each his own.