No windows in exchange for a discounted ticket; I think people will happily eat it up! If you sit in the middle of a row of ten seats (plus two aisles) the windows were just blobs of light in the distance anyway.
Customers have no real visibility into any of this, eg you're lucky to know what kind of aircraft will be flying a route let alone what interior configuration it will have (and all of that can and is regularly changed between booking and departure).
I'd gladly pay an extra $10 or $20 to fly with more legroom or a plane with windows, which would be a realistic reflection of what these cost carriers (10-20% extra), but these are major revenue centers for them. On the last flight I took, Delta wanted an extra $110 for an exit-row seat, on a flight that cost $165. That's just blatantly milking it. At time of departure, 5 of 6 seats were unfilled and they had to fill them with main-cabin passengers.
The only real control you have is over what carrier you fly with, and there are definitely people who will refuse to fly with budget carriers. By the time they are done nickel-and-diming you for having a carryon and everything, you end up in the same place anyway.
But even there, people only have a small degree of choice in carriers either. Delta is the vast majority of flights out of my airport (Wikipedia says 75%), I'd love to go with Alaska Airlines or someone but I don't really have a choice.
So, there's lots of reasons this isn't really an efficient market.
Lots of people say they'd rather pay more for those extras, but the evidence indicates otherwise. Lower prices wins custom.