Two stories:

First: Sometime in the late eighties, after the TWA Flight Attendant strike, a UAL new hire gets the jump seat on a TWA LGA-IND-ORD flight.
On the first leg he starts ranking on a flight attendant, calling her a scab, then he ranks on the pilots saying their concessions are ruining the industry. The flight attendant is in tears.
Guess who spent the night in IND because there were no more flights out that night.

Second: The classic story. Eastern was the first airline to offer jump seats. One night a DAL pilot was jumping BOS-LGA. The EAL Captain asked, conversationally, "When is Delta going to offer jump seats?"
The Delta pilot responded "At Delta our people consider it unprofessional to allow other airlines in our seats."
The EAL pilot is suddenly overcome by a wave of professionalism and says "Get the **** off my airplane."