Differing opinions, yay.
Seems to me that the very things that made me enjoy Hoenn has caused frustration for other players. I will have to concede that the endless sea of Wingull - Tentacool - Pelipper in mid-late-game Hoenn could have had better selection, although I can attribute it to Hoenn being a reboot, and they are trying to keep the selection to Hoenn Pokemon (and the omnipresent Tentacool). But yeah, some Pokemon that can only be encountered via fishing should have been available when Surfing, if only to break the monotonous barrage of seagulls and jellyfishes. Or they could have included Mantine and the likes.
At that point of the game, I stocked up 90 Super Repels, though, so I was fine.
I don't really understand the hate for Dive, though. To me it is realistically implemented (assuming that the HM Dive includes creating a bubble of oxygen surrounding the Trainer). There are a lot of Dive spots, but they are all hit/miss, which means that there is no guarantee that every time you Dive, you will get results, much like in the real world. Perhaps other swimmers/divers have gone down and snatched the Big Pearl before you? Perhaps it is just a vast world, and there isn't supposed to be remarkable things everywhere, let alone somewhere as gloomy as the underwater? Or perhaps you'll just have to keep Diving until you find your own big discovery.
I also think that the amount of backtracking in Hoenn is justified because of the sheer amount of new things you can discover with every revisit. Some places made me revisit at least twice (Route 119, the Acro Bike-only area, and later the Waterfall area). This can be said for other Pokemon games too, sure, but Hoenn goes even further: the places you revisit become shortcuts that connect cities like how cities should be connected in a region. I mean, in comparison, how disconnected is Mistralton City, really? It's not like they let us use their planes or something, unlike how Dewford is accessible using Mr. Briney's ship.
I agree that 3rd gen in-game mechanics sucked, although that has nothing to do with the world map itself.
On a sidenote, I am finding myself walkthroughs for Pokemon Colosseum on Youtube to experience Orre. Somewhat.