I don't know why you keep saying Tomb Raider. There are no features, that I am aware of, that don't run on both company's hardware.
Tomb Raider was not really playable with all effects on nVidia based systems. It was a lock out of people. A lot of them needed to wait 2 weeks to play through the game.
AMD knew that and used the unplayable version of the game to highlight their cards:
http://blogs.amd.com/play/2013/03/05/tomb-raider-tressfx/
So, i really want to see why people should "realize the importance of this".
Tomb Raider is a "true" GE title. And it shows that AMD tries to sabotage the gaming experience on nVidia plattform.
Both games had performance and stability problems with nVidia hardware. And both were GE titles.Same with DA2 and Dirt Showdown. Maybe I've missed something and you can fill me in?