Yeah, I never understood the complaints about surfing. The swimmers are the same as the trainers on land who challenge you, and if you don't want wild encounters, just use a Max Repel. The music is pretty nice too - the only drawbacks I can think of is not being able to move as fast as on land (you can't have aqua bikes), the lack of underwater secret bases and the annoying currents that move you around. But none of these are major problems.
I also don't think it's the surfing that makes Hoenn unique (you Surf in every region) but the diving. It's the only region with those extensive diving spots and underwater locations, and the only region where Dive was an actual HM. Surf is a key HM in every generation.
I have to say, though, it's no longer as much of an achievement to get through the "hard locations" anymore. In RSE, Sky Pillar had all the cracks and was a pain to get through, but it was very rewarding at the end when you got the face Rayquaza. In ORAS, Sky Pillar wasn't challenging to get through at all, and Rayquaza of course, is a required catch, so they increased the rate to 45. On the other hand, we did get a very nice history story as we progressed through the Sky Pillar in ORAS, whereas in the original Ruby and Sapphire, Rayquaza had no relevance to the story whatsoever (in Emerald, it gets more of a backstory, but there isn't enough on it stopping Groudon and Kyogre).
Similarly, the original Mirage Island was an absolute pest and a pain to get to. I'm actually thankful that the new Mirage Islands are so much easier to get to and aren't pretty much luck-based, but of course it isn't much of an achievement anymore when you get to one.
On a side note, I miss roaming Legendary Pokemon. The absence of it in ORAS is a bit noticeable, to me.