OT, but my experience is far more contrasted than yours. I have had the "PDB lottery" ex-US with most if not all European airlines. It's a frequent object of discussion on the BA forum and I have had the same on - among others - LX and AY. similarly, on various US airlines including DL and AA, I have had some "cheap" sparkling served as PDB where Champagne was offered on the flight, presumably for the same reason. It seems to me that the US is being fiercer about taxes on alcohol served "on the ground" compared to most other countries with the exception of "dry" Muslim countries for different reasons, and it seems that US airlines are always a bit hesitant between giving in or trying to play hard ball.

I agree with the general sentiment that when it comes to a product like AF P, it feels unnecessarily petty when staff make you wait, but when it comes to J, I can see the airlines' point - If you think of (for instance) a high J BA 77W, that is quite a few Champagne bottles on which to pay US duty when you offer it as PDB.