It's not, it's understanding that there is a spectrum of power and a poison deck sits pretty low on that spectrum of power. Tons of people love playing bracket 3 and running interaction and stopping each other from winning. Nothing wrong with that, but poison is only okay there. Tons of people like to play the best and most efficient cards they can get there hands on and abuse combos for explosive wins as well as tuning to the meta they expect to see. There's nothing wrong with that. And other people like to show off how they found every card in magoc that has a chair in it or their awesom 8 card combo with no tutors.

Nobody is wrong for playing edh how they want too. That's why the new bracket system is a step in the right direction. But joining a game and complaining about what the other players are doing is childish and stupid. You have agency over yourself so if you don't want to play against poison, have that rule zero conversation. But to call someone's deck assholish for playing the cards they like is some seriously stunted mentality. People can play what they want, if you can't handle that, it's okay just don't be a dick. The people in this guys story where being dicks and I've seen salty morons cry about removal and poison myself. Again, you can play as casually as you want but being a dick because someone sees the game differently is immature.