I can understand why this would piss photographers off, but I can't agree with the "justifiably" part. When I ride my bike home from a bar instead of taking a cab, the cab driver might be pissed. Should he pissed at bike manufacturers? I'm sure horse whip makers were pissed at Ford for selling cars, and lowering the overall value of their industry. Why should photographers get special protection from market forces?
Yes, but I think you are missing an essential point in your examples:
a) A bike is not really a replacement for a cab (say you want to carry some goods)
b) Cars are a different technology from horse-carriages
The thing is that the photos produced by all kinds of photographers are almost the same ( of course, the better ones produce photographs of better quality, but they are still photographs).
I think that the analogy that you used was perhaps not accurate..
It doesn't matter if the service is exactly the same or not, it just matters whether it meets the need of the consumer. In my example, consumers needed a way to get from point A to point B. Both a cab or a bike could do that. If you prefer, I could have asked if Ferrari should get pissed that Kia is offering cars for a super cheap price. Then we are comparing cars to cars.
