What you say is true, but I fail to see the point. There are still those who hold Calvinist-like beliefs who identify themselves as Christian, and the central tenet of the divinity of Christ, (Filioque aside), remains the same across Western Christianity. Some details of belief and observance may vary, but the Bible remains the central thesis. What's more, there is a remarkable consistency across denominations in what is touted and what is ignored. Try to find, for instance, a congregation whose leader has informed it of the full ramifications of Luke 19:27.
I might add, little has changed since Ambrose Bierce defined a Christian as, "An individual who believes the Bible is a divine text, perfectly suited to the spiritual needs of his neighbor."