I just don't buy this argument, which is oft made here on FT. Take for example Singapore Airlines. Their suites product is not available on miles, or at least only to KF members at truly extortionate rates. People in these suites paid for them. They don't even do op-ups - they pay people to take delays or downgrades. Try to find award availability on EK and you'll reach the same conclusion. While I agree that maybe on say AA there are a fair number of corporate paid J clients using VIPs to get to F, in general I am sure it is greatly overestimated the number of people in F who did not pay for it

That said, I've never paid for F. I have however paid many times for J, and would not travel over any ocean without being in at least J. But for sure I will try to use miles to make it reasonable.