I think part of Pokemon's problem is that Gamefreak doesn't grow with technology and are still using a lot of the same graphics engine people they have been using since 1996. For the most part, they just leave it to other parties to make graphically impressive things with Pokemon designs.
This is all wrong...
Gamefreak are one of the few developers who optimize their games for the 3DS. The amount of content they added in the 6th generation Pokemon games is alot in comparison to the previous gens. Going full 3D in 6th gen meant that they had to create new assets for pretty much everything. As the peeps were praising the 6th gen games for their models on the actual Pokemon in battle(you know the meat of the game) they were focal point. They are the equivalent of fighters in a Fighting game...
Lets be honest here, with the sheer scale of a Pokemon game, there was no way everything in the game was going to be as detail as the battle models, doesn't matter how you slice it, that is a tall order to fill. Especially considering all the content that was added in this game such as the trainer customization which is something isn't present in ORAS.
All things considered, 6th gen Pokemon games are actually visually impressive on the 3DS. Then again, MGS3D, SSFIV3D, Tales of the Abyss, and Senran Kagura 2, also impressed me so I guess I'm easily impressed.