A lot of folks wish the would, but ultimately, the goal for them is to reach the most people possible. And this isn't just a Square Enix thing. Most publishers are still supporting last gen as it still has a gigantic active base. The exception would be something like SF5 and even that is coming to PC.
In reference to Tomb Raider being held back because of Xbox 360, I would defer to Forza Horizon 2.
Another argument is that having the game on the 360 means that purchasing an Xbox One isn't necessary to play the game at release... which is true and I don't have a solid argument against that point.







