The quality could be fine. The fact that it isnt, has nothing to do with the idea that you pay for the food you eat. Other military and civilian organisations manage it.
Now singlies have more money to spend on booze at functions because they aren't automatically paying for their food.
It was never better value for the singlies unless the singlie regularly ate it the cook house. The majority didnt, thats why we have all the rose tinted glasses view of eating high quality food all the time under the old system.
The joke about 1 sausage partly stems from chefs only having a limited amount of food due to the numbers wanted fed. Normally in training establishments.
If everyone had gone to the cook house all the time the quantity (and possibly quality) would have been shit.
We may have different experiences with different units, but where I was pre PAYD most livers in took most meals in the mess. I probably took 15 of the 21 meals I paid for. Given the quality & quantity delivered I still considered it excellent value for money.
The quality was always going to massively suffer with PAYD, because the money per meal available was slashed. This created a downward spiral as both livers in and livers out abandoned the messes (one unit I was at saw lunch attendance halve within a month of changeover and never recover).
I don't argue I've been treated more fairly under PAYD, but my quality of life during the working week has suffered.