It seems like this post is choosing a convenient point in time start its argument from. The reason cheap airlines like Spirit came about was because there was a market for cheaper tickets with less amenities. The post says that the major airlines lowered the prices of their lowest tier seats to match these cheap competitors, but this lowest tier had more amenities. Now the major airlines have come up with a new lowest tier of seats (basic economy) and are setting their old lowest tier (economy) back to the higher price that it used to have.