Hmm, not sure about this.

I work hard to maintain my silver status for one reason, and one reason only - the ability to assign seats. (I get lounge access through the cabin I book anyway). But in recent months BA have made this more difficult by offering seats for purchase to everyone. This does mean that, despite investing thousands each year to keep silver, I'm at risk of not getting my preferred seat(s) because somebody else has paid £60 or £80 for it. That's considerably less than my investment each year (I'm not that young either, and pay for my own tickets!)

If you offered seats through miles there'd be even less availability for golds and silvers and I believe that's wrong.

I remember how furious I was when the ability to select seats was changed to only being gold and silver (in 2006/2007?). And that's what forced me to pursue silver. Since then there's been lots of chipping away at benefits for premium card holders and I think BA need to be very careful not to keep doing this.