TD Because the generation teaching it its current is an ad hoc explanation. --A definition of convenience specifically formulated to fix the predicament the JW's find themselves in today.
It makes no logical sense outside of that context and isn't meant to
Yes I've always found that to be rather selfish. The younger members of the GB are likely to be the ones left with egg on their faces when we eventually have a GB totally comprised of those anointed after "this generation'".*
I know for sure Mr Cook was NOT anointed when Ray Franz was alive. Therefore, though anointed, he is not part of 'this generation'.
So neither are any new GB likely to be (unless particularly old, which is not likely given watchtower's recent propensity to kick out older Bethelite's).
*Unless the Great Trib begins immediately!!