ALttP had the screen focused on Link, and the screens were much larger. True enough, sometimes open spaces are nice, but if every screen was open spaced, it would get boring. The screens also depend on what kind of area and how many enemies they have on them.
Look at the shot's you gave us.
Gashin: Gashin's first shot. I don't think there were any enemies, and if there were, they were probably keese, and it appears he has a boomerang, which makes them easy to kill. And the other shot has a mountainous area with only 2 octorocks. You really don't need the entire screenshot to fight 2 octorocks.
NoeL: NoeL's screen is pretty open. There's only 2 lanmolas, and their is plenty of space to kill them with. The mountains may look like it doesn't have a lot of space, but it does.
Radien: Radien's shot is perhaps the easiest example. It looks like an entrance to maybe a dungeon or another area. As far as I'm concerned, I didn't realize we needed the whole screen for an entrance to a dungeon or another area.
Well, I'm lazy, but I think you got the point. It's nice to have some open screens, but if every screen is open in your quest/, you're only going to get 1 or 2 stars in that quest. It's called "balance" Balance everything out, and there you go.
By the way, we have diagonal walking. But it's only for 2.11 betas