I too dislike the right/left classification. It didn't really exist until the French Revolution, and the attempt to stretch it into a universally encompassing political continuum has resulted in an impoverished view of politics, imho.
For instance, despite the similarities, I don't think that the prevailing progressivism in SV can be equated with classical Marxism, which is far-left in the original sense, since they disagree fundamentally on the most central questions to the Marxists, which are the centrality of economic class, and private property. I find the links between Fascism and far-right (again, in the original sense) Conservatism to be equally tenuous, given that they radically differ on the attitudes towards tradition and progress. Even the Republicans and Democrats don't really fit the mols. Think about it: what grounds do opposition to abortion and market liberalism have in common, really?
Trump doesn't fall neatly onto the line either, and I suspect that the tendency to place him somewhere on the old line has contributed to the rather confused, and reflexively negative reaction that many in the political class have had to his emergence and presidency.
It's best to think of political outlooks as clusters of positions in a high-dimensional space. The left-right model is like a poorly-executed PCA -- a reduction that confuses as much as it clarifies.