I said not more than half a gram Per pound of body weight, in my case that 100 grams, ( or more accurately a gram per kilo) i said nothing about 30 grams and nothing at all about it being rejected, the body doesn't reject protein , it just has no mechanism to store it, so you pass it on urine.
To be clear prOtein doesn't not make you grow, the exercise does that, the protein is just the building material for that growth, your body already makes its own protein from sugars. You need only enough to supply the growth your exercise has caused, any more is just waisted Down the urinal.
There are lots of people inbibbing massive amounts of protein supliment, saT there wondering why their muscles are not getting any bigger, . I'm assuming they only read the label and not the Small print
Nb, for most people who ARNt throwing big weights about, I suspect 30 grams is more than adequate