The remakes so far have typically incorporated aspects of the whole generation. FRLG not exactly, but it did include the Sevii Islands campaign absolutely for free.
HGSS involved Suicune more heavily in the story, and included a Battle Frontier (albeit Platinum's) as the original games preceded the invention of the concept.
That ORAS similarly features elements of all three Gen 3 games (Rayquaza's and Deoxys' prominence for example), but inexplicably skimps on one of the major postgame novelties of Emerald when there has been more than ample time to include it, is very disheartening. I don't think this bears explanation. Yes, ORAS doesn't "need" a Battle Frontier but it seemed like a no-brainer. It's an especially glaring omission when XY's postgame was chastised for being underwhelming, and GF basically went ahead and did the same thing again because they knew they could and they knew people like you would make excuses for them.
