I agree with your basic idea but I don't think it comes as any surprise that airline seats are all cramped solely for the purpose of squeeeeeezing in an extra seat in each row.
I certainly understand the airline's point of view in maximizing space and profits, but who is it that gets to determine how large a seat should be with an ever growing America ? and I mean growing in size.

Looking at the American furniture Industry, I doubt that they would sell many 17" office chairs.
Isn't it bad enough that tall people have to fly with their knees up against their chins?

Since a good deal of flights aren't 100% booked anyway, You would think that they would provide a half dozen or so seats at the same fare rate as normal seating to be best used as conditions dictated.

While I wouldn't go so far as to call the airline policies discriminatory, it sure comes close