I think part of the unpopularity of the generic brands was that, at least in the stores I remember, they were all segregated on an aisle full of generic product

I think part of the unpopularity of the generic brands was that, at least in the stores I remember, they were all segregated on an aisle full of generic products. So you had to specifically go down that aisle to see if there was a generic version of whatever you wanted, and there was a bit of a social stigma about being seen in that aisle. I imagine they would have fared better if they had been mixed into the rest of the aisles the way store brand products are today.