@Ed Long ..as they say its when you purchase, not when you sell. So are you saying that if a house sells at $90k and you purchase it at the right price(i.e. the flipping formula) that you won't make more than $10k profit on average? And on that note are you saying it isn't worth the time?
In my mind walking away with a $10k profit is better than walking away with no profit or a negative loss. Also, everybody has to start somewhere. Not everyone has the money to start working on the big $150k rehabs. Plus I would rather make mistakes and loose money on the smaller deals than loose on the bigger ones.
With Matt's story, its sounds like a few things happened. 1.) Maybe they should have purchased the house cheaper or included a contingency fund within the budget. 2.) Staging would have sold the house quicker, which would have meant less holding costs. 3.) Seven months is a long time to fix and flip, which doesn't help with holding costs either.
To me, they would have made more, if the rehab had gone quicker and they could have sold quicker. But you live, learn and move on at least Matt made something and he learned much from the experience.