It's because they don't. For most people, ethics are not a question of doing the right thing but about convenience. I have a boss who is doling out mandatory overtime (bonus -- I start at least two weeks of 3AM starts in addition to four hours overtime every night and the possibility of weekend work) while he goes golfing on the weekends and goes home at 6PM every night. When people complain to him, he says, "But you're making money!" He screws up, but doesn't have to bail himself out, we do, so there. People will cut each other off in traffic or just grab things without the slightest consideration. Survival and getting ahead become more important than your fellow man.
So The Avengers movie is out. Lots of people had misgivings, given how Marvel screwed over Jack Kirby and not only got away with it, but at times seems quite proud that they got away with it (Stan Lee said in an interview he has no idea why Kirby got a "created by" credit at the end). But for someone who wants to see their favorite characters, what are they to do?
Jim McLauchlin is part of Hero Initiative, a charity that gives money to help with medical bills and such for comic creators facing hard times. He decided on a brilliant idea -- pass the hat. You want to see the movie but are squishy about the backstory? You can give to them for their Avengers fund, and any money will go to Kirby's estate. That way, you can give something and be ethically pure when watching the movie.
Well, donations have finally dried up. Grand total contributions for a movie that made a billion dollars worldwide?
"What is honor? A word. What is that word, honor? Air."