Disregarding the ‘personal attack’ subdiscussion that this is turning into, I think that if you took a look at the instances of “veterans” beating down on less experienced players VS the number of people with any variety of experience coming on here and simply trashing everything from the game and its card/playstyles to the people that try to help them understand how to get over certain hurdles associated with the sources of their frustration, you might see where the toxicity actually tends to originate a pretty fair majority of the time.
I see a LOT more of people complaining about something and/or making entirely erroneous assertions (that a newer/less-informed player could come on, read, and believe) only to be provided with proper information and even a bit of direction,
(Also often made for the purpose of being viewable by new players perusing for information) then simply lash out at the replying poster(s) with insults and various vitrol than I do legitimate questions or requests for help being met with disdain from experienced players.
Social etiquette still plays a part even on internet forum interactions. You come in swinging and trash-talking everyone and everything, you can likely expect less hospitality than the guy in this thread got: