dg1, I agree. I do a) last minute travel, b) change my itinerary constantly c) don't know where I'll be tmrw, and d) want the highest status which I get when I spend money on full coach fares. I never stay Sat night, and don't want to screw with restricted fares. I've been there, done that, and find it a real drag.
I believe that all things being equal I should have priority if I am Platinum and have spent $2K for a coach r/t ticket vs someone who has spent $300, even if he/she is Platinum also. And I think this just makes business sense.