First off, one of the most common arguments against allowing women in the NHL is on-ice safety. Such an argument is a thinly veiled, misogynistic mask for saying that men are supposedly sooo-much stronger than women. This argument appeared often on Twitter and Instagram during the Women at the NHL All-Star Game controversy.
These thinly-masked arguments need to go, as most players whom played in the CWHL could very easily make an NHL lineup, and endure as much of a physically tasking game as those in the NHL.
Additionally, some of the best players to ever play the game are women, the most shining examples include Hayley Wickenheiser, Marie-Philip Poulin, and Natalie Spooner.