This is an oversimplification. Yes, obviously, anyone who flies lots of times a year cannot be losing out on upgrades more than once to someone who flies only once a year. But they can still lose out
that once, especially if lifetime status people tend to do mostly leisure travel booked far in advance, given that AA's current upgrade priority is based on time of booking within each status level. (Of course, AA could "fix" that by changing the algorithm for booking type, but for whatever reason they so far have felt that this simple algorithm is the best one.)
Furhtermore, the lifetime status person is not necessarily flying only once, but perhaps a few times. In fact, they may have LT PLT, and be flying enough to qualify for GLD for all you know, but they get PLT instead of GLD priorirty for upgrades. (Of course, I've proposed that there are probably way more LT GLDs than LT PLTs before, but I don't acutally have hard facts, just my theory.
)
Well, there's precedent. Somehow Delta went through this same process around 1997 (from all miles counting, to mostly only BIS counting now including alliance partners). Now, the landscape was different in 1997 (I don't think FT quite existed yet, did it?, and were people churning Delta credit cards then the way they churned Citi cards the past decade?), but Delta did decide that it wanted to do it
more like UA (BIS only
not including alliance partners) than staying like AA. Of couse, since it was at least the "second last" to change from "all sources" to mostly "BIS only", it wasn't "the only left" with a unique program the way AA has been since.
Btw, that's one thing BIS only proponent(s), like
favalarry69, don't take the time to make clear: If you think it should be BIS onlly, should it be Delta-style BIS on all elite-earning metal (ie, simply lifetime EQM), or should it be UA-style BIS on AA metal only? Why does one major competitor think it's better one way and the other think it's better the other way?
(Actually, the same question can be asked of anyone who feels it should be more than BIS only but less than "all miles count".)