The Confusion GT is a good example of this phenomenon! I love the Confusion, which is eerily identical in width to the 1997 Cold Fusion GT / Turbo Bumble Bee GT. Those were considered “wide” back in the day 
Confusion – great responsive!
Confusion GT – 
responsive. I keep mine unresponsive.
Here’s why:
And yes, the GT is less tall too, 56mm vs 54mm 
Which phenomenon? Sry I’m a little…confused
Width being bad for responsive play.
I couldn’t really get into the genesis. Just don’t like how it plays.
But why is this phenomenon unique to metal yoyos and does not afflict plastic ones?
I don’t think it is specific to metal.
Duncan Butterfly XT is 36.5mm wide, for example. Compared with the Shutter Wide Angle which is 48mm wide, and the Horizon is 43mm.
The Confusion GT is just under 43mm wide. The First Base, Replay, Arrow, and Sage are all in the 40mm - 43mm range (with a slim bearing) and they play just fine responsive. I’m simply not convinced that the Confusion GT plays poorly in responsive mode merely due to its width.
It’s not exactly width, It’s low walls the ones that are bad for responsive play.
In summary, high walls help for consistent response and stalls/responsive tricks.
Why would the high walls help for response? The silicone pads provide the response. Are you thinking of classic fixed axle wood?
Walls add friction regardless of material, high walls more than short walls. Simple as that.
What @jhb8426 said. A zero wall yoyo with a slim bearing will play responsive… But high walls act as an enclosed area for the string to wrap up right after the response pads had done their job. Also, high walls help for almost any responsive trick.
with responsive tricks, walls are much more about CONTROL than response. because the yo-yo spends more time starting and stopping, the yo-yo is more susceptible to changes in its angular momentum and higher walls provide more control/leverage. This is especially true of stall tricks, flips, regens, etc, but applies to any situation involving response. i do a lot of “responsive” style tricks with unresponsive yo-yo’s - on a wide H shape for example it’s really hard to start and land a varial, because you have little wall to push against and the yo-yo lands without a lot of stability. with a rounder, more organic shape, it’s way easier because there’s more contact. i’ve had plenty of wider responsive yo-yo’s which work great - the shape of the yo-yo makes all the difference.
i think gap width, wall height, and response pad thickness are what affect a yoyos “responsiveness”, of course when equipped with a slim bearing.
Speaking of large responsive yoyos (horrible segue I know), does anyone have pics showing what a YoyoJam Cerberus looks like without its side caps?
Huh. I don’t think i’ve ever seen the word segue written out… 
Okay, it doesn’t look half bad with its caps removed (I am not a fan of its caps)!
I’m really curious how it plays, both responsive and unresponsive.