Two reasons... USA buy more SW than other countries and X1 is close to 60% of their HW there while PS4 is like 30% and usually on a healthy platform tie ratios are bigger on the console with less HW sold, because the buyers of said console are more hardcore.
duduspace11 "Well, since we are estimating costs, Pokemon Red/Blue did cost Nintendo about $50m to make back in 1996"
http://gamrconnect.vgchartz.com/post.php?id=8808363
Mr Puggsly: "Hehe, I said good profit. You said big profit. Frankly, not losing money is what I meant by good. Don't get hung up on semantics"
http://gamrconnect.vgchartz.com/post.php?id=9008994
Azzanation: "PS5 wouldn't sold out at launch without scalpers."