Because it's socially acceptable vs. ewwww all men are creepy pedophiles if you do so much as think an 17 year old girl is sexually hot (without even knowing she is in fact underage).
Things like this that make the whole MRA movement come about, which isn't surprising.
Shrug, 17 is legal in a lot of states.
Damn, I just looked it up.
31 states 16 is the age of consent in 8 states it's 17 with the remainder being 18. So in almost 2/3 of the states a 40 year old can legally bang a 16 year old.