There’s a difference between the two leagues but it might not be as black and white as one would think. Back in 1996, NBA Mahmoud Abdul-Rouf, born Chris Wayne Jackson, was suspended and eventually blackballed for protesting during the national anthem, calling the American flag a symbol of oppression. He left the NBA to play for various other teams internationally.
Seventeen years later, in 2014, Chris Paul, Blake Griffin and a number of other players protested against their own, Donald Sterling, after a recording surfaced of him making racial remarks about African Americans and black players, primarily Erving "Magic" Johnson.