Why was NBC's checkbook journalism wrong.

Not only was it irrational, it was also unfair and criminal-like: not good for their reputation at all.  Not a wise move on their part at all, especially if they are focused on keeping their rep in tact.  If I were NBC, rather than risk my ego for a small story about airplane survivors, I would focus on something else to grab the audiences attention that doesn't involve the un-honest way of getting stories.  Going all that way to get a story will only end up wrecking you and you will have to spend a large amount of time repairing that trust with the audience.  It also makes the survivors look greedy to the average viewer since they "sold" their story, so it affects more than just NBC news.