What would be more feasible would be to offer a "fast track" to Gold for those who have racked up 10 or more years at that level.
This could work such that when they retire/reduce their travel they would still have to fly a reasonable amount on BA, but that they perhaps earned double TPs on all flights, therefore still requiring a regular, premium spend on BA (so avoiding the "something for nothing" brigade) but giving them more bang for their buck - a loose equivalent of the EuroCheat formula of old.
That would keep Mr and Mrs Middle Management happy on their two/three longhaul Club World trips per annum without expecting them to jet around the US on pointless journeys to enhance their sad, empty lives.