I think I know why people myself included like Hoenn so much.
Look at Kanto, Johto, Sinnoh, Unova, and Kalos. They seem to all be set in Temperate climate zones. Hoenn is the only region in the main games to have a Tropical climate. The feel was different in comparison to the other regions and Slateport City, Mossdeep City, Mt. Pyre, etc.

I really wish GF will try some new areas out in the future and stray away from the "safe" zones.