HGSS are remakes in that they are GS in the same principle, just refined with better graphics, updated Pokemon stats, tweaks and added Pokemon/events.
Anyway I like remakes, they are older games but better. If a classic did not age well for whatever reason it is best to give it an updated remake, such as Final Fantasy 4 on the DS. It's also a good way to introduce a newer audience to timeless classics such as the aforementioned game or Street Fighter 2. I'm also looking very forward to Persona 4 Golden on the Vita. (despite some of the added stuff being fanservice...)
On another hand, they should remake F-Zero GX for the Wii-U. That games is already perfect on its own and it's hard to top perfection if they want an F-Zero game, so if they wish to follow the same formula a remake is the only option with better visuals and added online mode.