I think you are ignoring the reality of the relationship between the US and Turkey.
We need Turkey (arguably) to have an airbase in the region. Turkey is perhaps the worst “ally” we have, and Erdogan is not on our side. WE neither belong in Afghanistan nor Syria, but we also injected ourselves into a civil war which got complicated by the rise of the IS, enlisted a minority ethnic group to our side, and now are abandoning them yet again. We may not belong in Syria, but we owe something to the Kurds who have historically been repressed by both Turkey and Syria.

As to the “prognostications” we did not in fact withdraw, but simply moved to a different area, so it was not Trump’s move that was brilliant, but the refusal of the military to actually withdraw from Syria.