Well, I am unqualified to put words in Father Z's mouth.
When I read that, I interpreted it to mean the assembly-line like fashion where EVERYBODY gets up to receive communion. A person sitting out because he/she acknowledges him/herself not properly disposed to receive communion is a rarity (at least in the majority of parishes I visit) and would stand out like a sore thumb.
People could use sore-thumb-hood as an evangelical opportunity. (If only to evangelize for “None of your business.”)
I think the practice of blessing a congregant who does not receive Communion has more to do with families’ bringing young children with them, since you can’t leave them in the pews most of the time.