Have you ever seen Slicky's textures? He has very little technical skill, at least up against the bigger names in texturing. His textures are almost entirely spliced, sharpened, and shadowed photos. However, he reaches a level of realism that not many other people can match.
Clearly, resizing a photo does not make a realistic texture, as it sticks out like a sore thumb and will generally look terrible. On the other hand, there is no texture artist who consistently creates textures of a decent variety of subjects and types that can start his textures with a blank document in Photoshop.
So I think that for a refridgerator, you're free to use photoshop only, because you clearly have the skills to make a good looking fridge by hand alone. However, why waste your time using the same technique to create a grass texture when you could use photos as a base?
I think it breaks down like this, and I use this as my own style: feel free to use photos so long as you are in control of the texture's specifics, not the photo. Mix photos with overlay styles. Photos should be for material, not real details upon the texture.
Beyond that, remember that the object of your texture art is not to follow a strict moral code for their creation, but number one, to look good, and number two, to look real.
[addsig]