Originally Posted by b12e

I believe it's the same for Air France, and totally understandable.

I wouldn't want to share the 2-3 J lavatories with 21-28 Premium Eco passengers when flying in J effectively almost doubling the amount of pax using the lavatories - and extra foot traffic to the front one(s).

At the same time, adding additional lavatories just for the PE cabin seems excessive (J has 2-3 lavatories for 30-38 pax, so you'd want to add an additional 2 lavatories to the total for 21-28 pax, which is extra plumbing, extra weight, less seats to sell, higher ticket prices for everyone).