OP, I'm not sure what you're getting at. You've correctly identified that airlines are just matching supply to what customers are willing to pay.

There are numerous options out there - in addition to premium economy, many airlines offer economy seats with a few inches of extra legroom. See Economy Plus on UA or Economy Comfort on KL, for example.

If you don't like what AC offers at the price point it's offering it, vote with your dollars and take your business to someone else who does. If that requires a connection, so be it.