I think a distinction really needs to be made between the ease at which miles may be collected (double rate promotions, credit cards, etc.) and the ease at which they may be redeemed. Whilst there have been increased promotions post 9/11 to encourage travel (by both increasing mileage earning opportunities and making redemptions cheaper in a few instances), the key point regarding the 'value of miles' still remains:

The value of miles is closely tied with ones ability to use them. If there are more and more miles out in the public (and supply of award seats/redemption availabilities in general have not changed) their value has by definition gone down!

The same holds true with easing the barriers to reaching elite status: the more participants, the more crowded the space becomes and the less likely one is to benefit!

Basic supply and demand ... or am I missing something?