Couldn't agree more!
Mothballing Snow Leopard is one thing but actually disabling it from being retrofit into the new 'Lion'-preinstalled MBA should the user so choose, is a short-sighted and stupid decision.
It's not so much that Apple *disabled* Lion from installing on the 2011 Machines, it's just that the 2011 machines have new hardware in them (different Thunderbolt Chip, Different Bluetooth chip among others) that has no support in Snow Leopard, 'cause there were never SL-capable machines that had that hardware.
Of course Apple could release a SL-patch (10.6.9 anyone) to include support for the BT 4.0 and smaller thunderbolt chip, but why waste precious resources on supporting newly-Obsolete Software on new machines?