Are you really surprised you're getting pushback? Given the choice of building something or not building something, how many regular posters on this board are going to choose the latter in any given situation?Build the bridge so that the people in this disconnected cluster of apartments can walk through the giant parking lot to get to the mall.
Again, if your opinion is that there is no hope for unwalkable areas so there's no point in even trying (and, to infer, that those that are currently walking in these unwalkable areas don't deserve basic accommodation), that's fine, and you're lucky because MnDot (not to mention Roseville, Ramsey County, and most suburbs) seems to share that opinion. But again, it seems like the popular attitude on this board is that things should change - typically what should change is that buildings should be taller or should use less cementitious panels in their exterior, but in this case that at least some currently unwalkable areas should be made more walkable.
But if your opposition is more specific to this unwalkable locality, maybe you'd care to elaborate? I think that as a regional shopping center surrounded by relatively dense housing that is already mostly arranged in a grid pattern and is already well-served by transit, it's an ideal candidate for improved walkability. Why don't you think Rosedale should be made more walkable? Even though the existing built form is clearly hostile towards pedestrians, it is already dense enough to attract some walking, so improvements to the roadways are needed to accommodate existing pedestrian travel. Of course improvements to the built form will be necessary to make the area truly walkable, but do you really think that improvements to the roadways should wait until, say, there are no more drive-throughs here? What would waiting for even a predominantly improved built form to install sidewalks even accomplish? Finally, there are several thousand employees working within a half-mile of the Snelling interchange, and in the same area there are dozens of restaurants. Given the facilities are built, why wouldn't employees walk to these restaurants in walking distance (i.e. Har Mar is potentially a half-mile walk from MnDot if they build sidewalks and a ped bridge on the east side of the interchange)?