Parsers are tools that could fuel toxic behavior....but literally anything can fuel toxic behavior. A person having better gear than others can fuel toxic behavior, a person having a minion that someone else doesn't have can lead to toxic behavior, a person who buys stuff from the Mogstation can lead towards toxic behavior from others about it.
Toxic behavior exists outside of the MMO world as well and you simply can't just plug your ears and and shut it off either. People need to learn to stop fearing it and just brush it off sometimes at the end of the day as well. What a few jerks do to your time inside of the game should never spoil it completely.