Lets start a discussion and let the bean counters know how we feel!
Everyone's been letting bean counters know how they feel for decades. What they felt was that they'd much rather have a cheap ticket with less legroom rather than an expensive one with more legroom. As ExXB alludes to, the airlines with the cheaper tickets were consistently winning the sales wars, and to offer such low prices they had to cram in more seats. In other words it's customer driven.