The setback wouldn't be too bad if it wasn't facing a highway. Hurontario (or Burnhamthorpe, or any other Mississauga arterial) is simply not human-scaled. Human-scaled retail in a non-human-scaled street tends to be ignored by passing cars. There is a reason why strip malls and big-box retail have huge obnoxious luminous signs visible from hundreds of metres away.
Mississauga continues to build good things (universities, transit, condos) on horrible streets and grid-systems. Even if all of Mississauga's downtown was taken by high-rise buildings the way these interact with these highways would still not be conducive to pedestrian activity.