The most glaring problem is of course the lack of a substantial post-game content, besides finishing the dex and challenging the battle tree. Oh and some sort of contest/pok?athlon minigame of ANY kind would improve the game's longevity a lot. Messing with a silly in-game camera doesn't quite make up for that
The battle frontier in gen 3 and 4 were amazing in this regard, but even those don't come close to the perfection that was reached by B/W and B/W 2. The white tree/black tower challenges were great and the pok?wood was also a lot of fun.
You see, I think the main problem with pokemon games is that there's this FREAKING HUGE divide between casual and "competitive" play, even in-game.
Once you're done with the main adventure sudently your team becomes absolutely useless, and your only options after that are to either buckle down and go through the tedious and gimmicky process of actually raising perfectly IVed hexaflawless powerhouses with excellent egg-bred moves, or... just stop playing the game.
There's no reward for actually training and getting to know a certain pokemon aside from being able to tick it off the list so that one day you just might complete the dex. I want to be able to look at the pokedex and see which pokemon I haven't played with before,
I want to be able to go out and catch a Chatot or a Bewear and train them just for the hell of it, and to be able to actually DO SOMETHING with them. Even when that "something" was just have them participate in beauty pageants and spoil them with poffins and treats, it was still better than nothing, but now we don't even have that.
Hell maybe they could let us re-challenge the trainers of the region and make challenges based on that. I need to be able to HAVE SOME FUN with the pokemon I catch without being forced to raise them to perfection, ESPECIALLY since the only way to do so is to research that **** yourself because half the time the game won't even aknowledge the hidden values and stats that are vital to a pokemon's cometitive ability.
I love this series to death and I always will, but something HAS to change in this regard. I just want these games about catching and raising creatures actually let me do so and reward me for it.
I could sit here and preach about how I want all pokemon to follow you in the overworld or for the GB sounds from HG/SS to make a comeback but really, this is all I really want.