I direct your teacher to Christina Sommers, a feminist in support of the movement:

The prove it's not sexist part is near impossible. You cannot prove a negative. I would simply say that if there are over 10,000 people engaged in this campaign for over three months, why have they prominently harassed only three women? It's three too many obviously, but it doesn't add up. I'd also point towards TFYC.

It's also worth noting that harassment is a two-way street, with some data showing that traffic is heavier towards us. Look at King of Pol being sent a knife and a note to kill himself, and having firetrucks sent to his house, the emergency services having been told he was in the process of committing suicide (a lie obviously). Then there's Milo Yiannopolous being sent a syringe and a dead animal. The attempted SWATtings (calling heavily armed trigger jumpy SWAT teams on someone, which could easily result an innocent person being shot) of Margaret Gel and Mike Cernovich. Finally, there are allegations of an actual physical assault on Steve Tom Sawyer, based on his support of GamerGate.

These don't prove everyone opposing GamerGate to be a violent harasser, but you would wonder why these events recieved NO COVERAGE while other claims with far less proof were given a wide airing in the media.