[dude with glasses in a communist t-shirt, arguing] I'm the only leftist here, your opinions are TRASH
[dude holding a theory book on smug, arguing] Read theory you losers, you're all WRONG
[dude in an anarchist hoodie, arguing] Nuh-uh, I'm the only leftist here, you're SHITLIBS
[the three dudes are now caught in a cartoon fight, glasses gone flying, punches everywhere, while a firing squad of nazis are targeting them with rifles]
[a confused nazi asks] Why… why are they still arguing?
It does help that the overarching theme of the right is centered around taking as much for yourself as possible and not caring about the collateral damage. The right is full of single-issue voters who might, say, not actually explicitly hate gay people but who also don’t give a shit about their rights and safety if it means they can keep their guns. The left, almost definitionally, needs to consider the complexity inherent in not being able to ignore the effects that any given policy might have on others and this means that there is so much more opportunity for conflict.
You’re correct, of course, I’m just pointing out the difference such that it might help attack the issue from a better perspective.
There's the nuance the original post relies on ignoring. But it's supposed to be a humorous joke-post anyway.