Sadly, that statement also holds true for buttermilk. Most of what’s at tops or Wegmans is low-fat milk soured with lactic acid. Only brands I’ve seen make real buttermilk available in Rochester are Ithaca Dairy and Pittsford Dairy. I’d hazard a guess that most of the blue cheese dressings use a commercial scale yogurt process. Not really comparable to the real deal because, as you said, you lose all of the depth and richness.