When I grew up I was taught that if you can't afford something then you didn't get it. It didn't mean you were any less of a person, it was just out of your reach. If you wanted it badly enough you saved up until you could afford it. I still live by that principle.
Sadly, I seem to be one of the few in my generation that follows this. I refuse to buy on credit, and I think it's ridiculous that I need to have at least a small form of credit (line of credit, a card, etc.) in order for people to believe that I will pay them on time when renting or getting a cell phone.
However, going by the idea that if you can't afford it, go without, if the prices went up on airlines, fewer would be able to afford flying, (assuming they waited until the could afford it,) and the airlines would suffer as a result. Perhaps that would cause them to lower costs again, which would make everything work out in the end, but by what means? How many airlines would cut out areas, resulting in the loss of jobs? I am probably thinking on too large a scale here.
While I agree that airline seats should start reflecting our larger status, I do wonder about this: you say that the increase in cost resulting from larger seats wouldn't matter to you. Does that hold true if someone were to suggest that your family buy first class tickets (increase in cost for larger seats) instead of riding in business/coach/economy?