Good for them.
If they don't make money, this forum's days are numbered.

It's a la carte pricing. You get what you pay for.
If you think your "bags fly free" on Southwest, you're mistaken.
The difference is, you are paying for checked bags on Southwest, whether or not you check a bag. It's all averaged out and included in the price of the ticket.

Don't blame the airlines. Blame the travel websites (Orbitz, Travelocity etc). People voted with their wallets; the airlines are giving people exactly what they wanted (or deserved). This is precisely why you won't find Southwest's tickets for sale on any of those websites. When sorted by price, they Southwest won't be anywhere near the top on most routings.