However I find myself being disagreed with quite often, mostly for not advocating or cheering violence, "by any means possible" change, or revolutionary tactics. It would seem that I'm not viewed as authentically holding my view unless I advocate extreme, violent, or radical action to accomplish it.
Those seem like two different things to me.
Edit: TO COMMUNISTS, ANARCHISTS, OR ANYONE ELSE CALLING FOR THE OVERTHROW OF SOCIETY
THIS OBVIOUSLY ISN'T MEANT FOR YOU.
You are to the right of communists, who will not consider you “validly left” unless your ideology is anti-capitalist at a bare minimum. We consider capitalism to be the greatest cause of violence in the 20th and 21st centuries.
Alternately, you are to the left of fascists, who would consider you “validly left” as they rounded you up for the camps. Validity is all relative.
On another note, I think you massively misunderstand the difference between calls for revolutionary leftist violence and random people cheering on Trump getting shot, for example.