To be honest, I don't understand why people want remakes anymore. Gen I needed it because Gen I itself was an unplayable pile of garbage after a few years. Firered and Leafgreen not only got them up to par but gave us some nice content in the form of the Sevii Islands.
Gen II needed it because, while it was a bit better in the bugs and QOL department, it was missing core gameplay mechanics such as abilities and the physical-special split. HG and SS went above and beyond this, though.
By the time we got Gen III remakes you could argue it was missing the split as well, thus demanding a remake. However, the overall scale of changes was nowhere near the previous remakes and felt like they established a pattern of remaking every gen just because. Moreover, going for Ruby/Sapphire remakes instead of an Emerald Remake makes the story feel incomplete, which is why they had to create a side story with some Dragon chick to make Rayquaza relevant, instead of him bringing peace to Groudon and Kyogre.
When you talk about Gen IV remakes, I feel there is nothing that needs to be done. The core gameplay mechanics for the most part are already there. If you want to play the games, you can just put them in your 3DS. Finally, Game Freak's recent track record doesn't give me much hope that they will put enough care into the remake that it needs to be made.
That said, Gen IV is my favorite gen, so I am biased.
