To add to CX828's post - take a look at Turkish Airlines - they had what widely considered the industry leading PEY product and by the far the most comfortable - and they have now removed it. Why? Because it cannibalised their J. Take a look at LH which just introduced PEY - they have specifically not even made it a separate cabin because they were concerned that J passengers would downgrade.

Your statement that "rich" people don't care about the cost of J/F tickets is ludicrous. I have flown Y precisely three times in my entire life but you can bet your bottom dollar that if PEY was good enough I'd switch from J in a heartbeat particularly on a daytime medium haul flight if the saving was reasonable.