Nope, you nailed it. Furthermore, if the airlines had just kept their prices $60 higher than they are and never added baggage/snack fees people probably wouldn't be whining - and yet they'd still happily be paying the embedded fees. Obviously I'm assuming that the prices are fairly low - but I believe they are. I just made a 1300 mile (one way) trip that cost $250 round-trip on a major brand airline. With baggage fees it came to $300 plus tax...for that I flew on fairly new decent airplanes with seats I chose, with free drinks and snacks. Sorry but $300 isn't much.
As for the add-on fees through, I believe the biggest reason for them is so the basic advertised prices can be lower. People shopping for price-alone will no doubt be attracted to the lowest price then complain about add-on fees rather than do the math up front.
There are a handful of small airlines truly pouring it on with add-ons but the majority of the major carriers just aren't raking people over the coals.
Are there really that many people who shop by price alone and don't realize that the added fees will make their trip just as or more expensive than tickets offered by other airlines?
I wonder why some airline hasn't come up with an advertising campaign boasting of having no add-on fees like other low budget airlines?