Here's a thought.
You say about including the cost to the ticket price, and that people won't pay extra for an airline charging baggage costs in the ticket cost etc etc.
Why havent airlines thought to put the extra baggage costs into the Passenger Service Charge that we already get charged regardless of whether we want too or not? ( Not sure about the USA PSC?!?) Surely if they upped the PSC by say $20 per person, we wouldnt really know. that versus charging for every or extra baggage may (or may not) solve the problem. It is a "passenger service" carrying baggage after all.
Further to this the total fares would show the same plus "taxes" , as it does now, so airlines would still be able to complete effectively.
AND, passengers might stop taking their life's belongings into the cabin
...
Would certainly help me in my role dealing with complaints, as baggage issues are probably around 15% of all complaints we recieve ...