Yes it can happen on any airline, but it does happen on AA a lot. The monthly statistics, especially AA vs DL, bear this out. And when things go south on AA, they seem to really go south, as the OP experienced. AA management's priority is cost control and squeezing in as many pax as possible, with predictable results on operations. UA and DL went through similar periods but both figured out that was a dead end. It took the Port Authority scandal for UA to dump SMI/J. I wonder how AA will accomplish the same.