You will note from ExXB's post after mine in the above thread that there is no weight problem as "cube" or volume is more important for baggage.
I didn't actually say that. I said that in the '60s the US CAB came to that conclusion - but remember there were no wide-bodies in those days. Even if their conclusion was right then, I don't think it is now with the aircraft models operating today.
In the good old days governments were content with the airlines making 'agreements' amongst themselves, through IATA, on what the industry standards should be. In those days there was much more interlining and you needed these standards for the passenger to move 'seamlessly' from one airline to the next.
Today, governments want airlines to compete which means airlines set their own rules for these things (and to a limited extent - where authorised - with their alliance partners). Compete means prices go up as well as down as/when the airlines sees an opportunity to enhance their revenues. That is the reality and we poor consumers have to live with it.
While I relate to your comment about customer service - this really isn't what brings the customers back. It's price, price and price, in that order, that drives today's consumers.