These consoles have disc drives, they could play (almost) everything. Prior generations already had decent emulators that read them. If you insist on giving every game a special treatment or not enabling them at all, you end up with FPS-boosted Spongebob shovelware but still no way of playing Silent Hill 2 or Burnout 3.

It's nice that there is Ninja Gaiden Black in higher resolution or Nier Gestalt in 60 FPS. But if the price for that is having only like 12% of the games instead of 99%, then it was a subpar choice.
e: Also wasn't even the original Xbox HD-ready? These games would still look fine even without being boosted.