Whenever this subject comes to the fore, I tell the following story: Many years ago when I bought my first DSLR - a secondhand Canon EOS 30D - I was told to also purchase a copy of PhotoShop. However, browsing through the local camera shops website, I noticed that an EF 70-200mm f/4 L USM lens cost exactly the same as PhotoShop. I went with the lens, as it gave me a level of quality that PhotoShop could never fix that was lacking on my EF 75-300mm lens. Afterwards, the JPEG's were so good I never felt the need for post-processing. Moral of my story, excellent lenses trump PhotoShop.
However, I can see the value of PhotoShop for people who are constantly "upgrading" their cameras, or switching brands. In this regard they never quite learn all the ins and outs of the camera in the same way that we used to with film, and PhotoShop thus provides the constant on which they build their photography.