Some people are just jerks. I personally do not find the playerbase more ‘toxic’. I also think the word toxic is over used. Personally I have played other games where I would say there is lots of toxicity but this isn’t one.
I started in TBC and it’s a miracle I stuck at the game. People were horrible judgmental elistist jerks that gave me such a hard time as a new player, I just gave up on doing any group content with others. I ended up waiting until I’d outlevelled dungeons and go back and do them solo so I could at least see them.
It wasn’t until the groupfinder was introduced towards the end of WotLK that I actually got to enjoy any dungeons while levelling. And wasn’t restricted to having to please random people at max level or only be able to do things with guildies.
Because of my own horrible experience I go out of my way to help people who say they are new but not everyone feels the same way. If you are removed from a dungeon just do something else until your debuff is gone.