I can certainly understand those who have had bad experiences with archery equipment, but I truly believe there are easily explained reasons for the failures associated with it.
First is equipment.
I see a lot of archery gear sold that is bound to give problems, but hunters that have limited experience can't discern bad gear from good. Take cheap dull broadheads for example. Every year a new crop of cheap Chinesium broadheads come on the market. They are dull from the factory and can't be brought to any degree of sharpness no matter what you do.
Then there are quality broadheads that are so sharp you can easily cut yourself badly just screwing them into your arrow shafts if you aren't careful.
The cheap dull broadheads will likely result in a lost animal, even with a good accurate shot. The shaving sharp broadheads will leave a blood trail Stevie Wonder could follow, and it's likely to be a short one.
Second is training.
Others have posted that beginners don't practice enough, and I agree 100 percent. I'll add that anyone that hasn't harvested 10 animals with archery tackle should keep shots to 25 yards, and only move out farther after you've put a good number in the freezer.
A big point on training that I can't emphasize enough is having an experienced mentor. If you can find an older hunting buddy that has years of experience bow hunting, he can help you avoid most of the pitfalls discussed in this thread. Buying proper gear, bloodtrailing, etc. are all things we've been taught when gun hunting, but I've seen a severe lack of it in the Archery World.
We as hunters need to help each other to do better.