why don't they just say "The numbers below include fees" or "don't include"?!
Because these are accounting documents, and the terms accountants use are "gross" and "net".
Think, for example, of your paycheck. Your gross pay is your rate multiplied by hours (plus bonuses, etc).
Your pay net taxes is what you get after taxes are deducted. Your net pay is what you get after taxes, insurance, 401(k), union dues, etc are deducted.
Thus, "The numbers below are presented gross of fees" means "before fees have been deducted".