I am no expert on Quincy zoning regulations, but I wouldn't at all be surprised if that setback is required. Bad street levels are often the product of zoning rules, not the product of developer decisions in spite of them.
Maybe zoning requires the setback on this block? But the buildings on this site beforehand weren't setback. And while it's entirely possible that they were built before any setback requirements were implemented, this new(ish) one across the street doesn't have any such setbacks. I'm no expert either and I know it sometimes happens, but it seems odd that the setback would be required here and not across the street.