It certainly will take a long time for anyone to reach lifetime gold if their travel isn't extreme. But I guess that's the point, people with lifetime gold really will have shown true loyalty to BA over most of their career so gold status in their last few years of working, when travel may be reducing but the comforts of gold will feel even more needed, would be really appreciated. Then when they get into retirement it really could drive loyalty when without gold status leisure trips might have been booked without thinking about airline preference. It may even drive significant leisure travel to BA Holidays rather than local travel agents etc.