It does show that at a 100% load factor there is a very low return, but at the industry average of 80-85% there is a constant loss.
The fallacy in that statement is the same as when people say : "The flights are always full so they must be making lots of money."
It's not about load factors, it's about yields. In theory, if you filled the front of an aircraft with full F and J class passengers, anything else could be pure profit.