Very true, I must admit this whole thread has made me chuckle - its like going back a 100 years to the Titanic when first class passengers were mortified at steerage travellers being seen in their presence let alone the fact they even have the means to be on board.
If money was no object we would fly upper class ( but then wouldn't anyone

) for us we are all small so economy gives us the sufficient space and we would prefer to spend more on a better hotel when away. The idea that having economy passengers in the bubble devalues PE, whilst true to a degree does not mean that PE passengers would have a more unpleasant trip - after all money does not buy true class and you could equally be seated next to the family from hell wherever you sit!
But you never know - maybe virgin will vett economy passengers sitting in the bubble to ensure the can be trusted to behave an mix well with those in a higher class!!
(disclaimer: I am a huge fan of irony and study class differences and people's attitudes - do not wish to offend anyone but just wanted to share what I found an amusing outlook on this thread)