If you creating photography as a(n):
a)product: then photoshop is certainly a good tool. It's cheap, efficient, and quick. In this case photography is the means to an end. This does not necassarily mean to sell as a product, but your goal is to simply get the best picture. Photoshop is certainly an extremely powerful and creative outlet, but it's not a photographic one. The trend (I said trend, not all, not everyone) I have noticed has been that more people with highly capable digital cameras have no hint of photographic knowledge compared to those with real cameras.
b)art: then photoshop defeats the purpose. Creating photography as art is as much about the means as the end. It's not about efficiency or speed. Painters pain, musicians compose, photographers photograph. It's photographer, not photoshopper.