Protestantism isn't inherently left-wing. It was an attempt to turn back to the Early Church and the Church Fathers. And it wasn't the cause of leftism in General:I have posted this a few times.
In British history, which most of the world has synced to there has been liberal to conservative waves, since the emergence of the original left-wing movement (Protestantism).
I am not left-wing and neither is any resident Protestant here either. Sure heretics took advantage at that time but making it all about us isn't accurate and not the way to go.
Many left-wing ideas come from the humanities. Like the Utopian Plato's Republic. Democracy and so forth.