The reason for that is obvious, the contradiction of trying to combine conservative economics with a left wing social agenda in the open where people can actually see it, does not win many voters.
The only way that libertarianism can prevail, is to either corrupt the democrat party on economics, or corrupt the GOP on social issues and Christianity and traditional Americanism.
There’s no such thing as “conservative economics”. Now, if you were to fuse libertarian economics with traditionalism, you might have something. Seems like there was a guy you claim to admire who said something about that kind of thing in a speech. I’m sure he didn’t really mean it, it was early, he didn’t say it enough times, and other dishonest evasions.