As a professional photographer, I can safely say that YES, most photographers would be outraged and you'd probably face legal action for not only using and altering their images without permission but profiting them from as well. This is hugely illegal and unethical and you'd be surprised how recognizable images can be.
I greatly disagree that this is common practise in professional graphic design. As a photographer, I've worked with many graphic design artists and NONE of them would even dream of doing this. They use stock images and they pay for them.
Time? It would take little to no extra time to search stock image sites than it would Google Images. Typically, the excuse is "I don't have the money" but stock images are generally affordable too. Here's just a few stock images sites:If I tried doing things the 'legit' way I would soon be out of a job as I simply haven't the time.
"Oh well"? Would you be saying that if someone took YOUR work without permission, altered it, and then made money off of it? Oh well? I flabbergasted that someone who produces his own creative works is so flippant about blatant copyright infringement of someone else's creative work. You seriously need to reassess your moral compass.For the book cover I could have taken the time, granted, but I had been told by someone I respected (should have checked up) that if one makes changes to an image it is no longer in copyright. It seems, after investigation, that that is not the case. Oh well.