After the mergers of airlines, they realized that they have a captive market and don't have to care about service since there is only a limited number of choices for a large customer base. It's far more profitable to treat the customers are cattle who have no other option.
Oil prices are down, but the fares are still high. The seats are small, service is terrible, airports are congested, TSA is intrusive and the experience is horrible, but what can we do?
It's like internet service. When you have one or two large monopolies controlling an area, there is no incentive to treat customers well. Get mistreated by verizon go to comcast for more mistreatment.
It's funny looking back when airlines were merging that the CEOs were saying how cost savings and synergies of merged airlines will trickle down to the customers in the form of lower airfare and better service.
It was supposed to be a win-win for the companies and the customers.