I think the main problem is that the mindset that mileage loyalty programs try to instill through marketing is that you are getting something for nothing through your loyalty. Just fly us regularly and we'll send you to paradise for FREE!

I can't see the success of advertising "Spend $4000 with us and earn a free ticket to Hawai'i!" because it puts the $ figure of travel and the realistic cost of acheiving an award in the limelight.

A lot of airlines already have public or semi-secret programs in place to reward and recognize their high-revenue flyers.

One could argue that the credit card hotel points/miles earning cards acheive to some extent what you suggest by equating earnings to $ spent, but they are banked points/miles rather than elite qualifying.

Oh, and it'd really kill my mileage runs.

peace,
~Ben~