You have a problem with their behavior because your sitting in front of your PC, not surrounded by a bunch of machine guns in an open boat.
Maybe the Marines (the 4 of them) should have opened fire and then they could all have been killed, but the internet-commandos would be happier in their cartoonish bravado, and we could post silly things like "they died fighting" or whatever hallow nonsense would seem fitting, then we could go and make lunch and turn on cable sports.
As for them selling their stories? who cares, let them sell their stories, they got approval from the MOD to do it.
They were not at war with Iran, they were not fired on, and it was common sense to do what they did. As for the vidoes, those were coerced.