The problem is that first class takes up much more than 15% more space per person than coach. You'll notice there are three chairs per side per row in a standar

The problem is that first class takes up much more than 15% more space per person than coach. You'll notice there are three chairs per side per row in a standard 787 coach, but only 2 first class. That's 50% more right there, plus there's more leg room so it's worse. Their margins are already thin even packing it as they do, so at only the equivalent of 2/3 current capacity that would be a recipe for failure. They'd have to charge probably twice as much.