The recommendations for protein vary. There are those recommended by weight (as your say), but those in training (ie trying to gain more muscle mass) take more. Seniors in particular need to be careful as too much protein can amp up immune system and/or be harder on kidneys/liver. I suspect the "upper limit" is based upon age and activity levels, not yet widely understood.

One might say that several "happy mediums" are not yet well understood:

1) How much cardio or strength training before there's too much stress on joints (again, probably age and activity related, not yet well understood)

2) How much do we mute inflammation in old age? Too little inflammation is bad also (ie just look at all those Humira warnings)

3) You wrote an article basically saying "Milk = Bad", yet to qualify that, for elderly some milk is good (too much may be over 2 cups per day, but lots of conflicting info on this). Many qualifiers on that!