What you are missing is "motivation". If you are not paid well, you will feel bad going to work, and you will be frustrated and unmotivated. As a result you will not say and act in a nice way.

When I used to fly Delta colors, and when Delta started to give us the worst schedules compared to all the other code share partners, I did not feel the need to do my best to comfort their pax. I was professional, but I damn sure did not go out of my way. It is this "you F me, I F you" attitude.

Normal human nature. Motivation is very important and it is directly related to pay. Unfortunately pay is directly related to the company's ability to pay. Which in turn is related to the product and their profit margin. If they sell cheap tickets, and can't keep cost rock bottom than they will have to cut pay and other expenses. Perfect circle.