Are inherently un-demised retail spaces bad retail design?
Yes ( in terms of exterior appearance ), actual walls on the inside that are not load-bearing are not required in advance of leasing; however, larger units tend to preclude a variety of retailers from being potential tenants as it brings the total rent out of their price range and also has them taking on space they simply don't need.
Are walls of glass at grade bad retail design?
Yes; because they result in lower customer footfall, lower rates of 'discovery' and less 'branding' of retail identity, and rarely create any interior visibility (see window wrap) Retail works best with deep, but narrow units which result in lots of space for storage, back offices, washrooms as well as areas to display things which then frees up the street-facing windows for inviting displays.
I'm assuming the goals are maximum flexibility and visibility / transparency. And I'm assuming those goals are met.
Flexibility, as noted, occurs when one chooses not to build non-structural walls pre-leasing, that's fine. But it shouldn't appear to be that way from the outside. There is no material change to functionality from giving the street wall 'apparently' demised units.
On the second point, see window wrap above. Units heavy on glazing end up seeing fridges, freezers and shelves up against said glazing, which then requires drywall and/or window-wrap up against said glazing.
Otherwise, we wouldn't be seeing these in new developments all over the place.
Have to disagree. We see this because it makes the architect's life easier, because it's cheaper for the client, and because neither understand what works from a retail perspective, and/or don't care.