Opposing fascism isn’t far left. That’s just being a decent person.
This meme is made by a leftist, and that community does have an issue with the same “if you don’t explicitly agree with everything we say, you are other and therefore evil” attitude that the MAGA crowd has.
Leftists barely agree with each other, let alone anybody elsewhere on the political spectrum. You aren’t entirely wrong, though - there is a tendency to say that anything good is leftist and anything bad is right-wing, but right-wingers also do the same (see how anytiing they don’t like is either woke or communist, or both)