We've had a few low cost carriers go out of business in the UK with a significant number of comments remarking on how these airlines were 'ripping people off' despite the obvious evidence that they were not charging enough.
Sometimes you get a problem, extra luggage fees, unplanned check-in at the airport etc. so that you are forced to pay much more. But counting all together they are still cheaper and more affordable.
People complain when they have to pay but forget to mention those times they paid much less.
Or maybe those people have higher needs, more luggage, less experienced with online bookings etc. Well, they are not happy that they have to pay more but for those who travel light, book, check in online and go, can still benefit. Why should we force them to pay more by forcing airlines to provide services that they don't really need?