It’s not that people didn’t like the open-ness of it but how bland every water route was with only the log town being noteworthy (and even that place isn’t really interesting too). And the Dive sections aren’t any better either.
Yeah, and the wild Pokémon random encounters that you'd find everywhere. I felt Route 9 was executed pretty well largely because you weren't running into wild Tentacool or Frillish every five seconds if you weren't battling someone. You can see every Pokémon that pops up, and the ones that chase you down, like Grapploct, can be evaded too.
The issue that might still popup, however, is the wideness of some water routes, which causes you to miss things if you don't scour every last bit of it. This was a problem I had with the Hoenn games. It was pretty nice to be able to wander around the eastern area, with its archipelago and all, but they'd hide goodies, trainers, and other things that might be necessary to proceed. For instance, I somehow briefly got lost playing
Omega Ruby and couldn't find Sootopolis City for like 30 minutes.
All the water might lock people out of Isle of Armor if they haven't gotten the bicycle upgrade as well. I'm sure the story stuff can be done entirely on that one main island though.
From what I've seen, the majority of the folks complaining are those who haven't even played Sword & Shield.
Same old Dexit mess.
To be fair, the people who didn't play
Sword & Shield are in a worse spot, since they'd have to buy one of them AND the DLC, which will cost a lot more than just starting later. That's why I think there's an advantage, albeit diminished, over releasing a standalone game. People can start there instead, which seems to be a pretty popular thing to do in Japan (which is to start later into a generation, sitting out the initial games). They'd have more reason to be upset about the DLC route because the barrier is higher for the ones who haven't taken the plunge.