National Socialism had a complex relationship with technology. It was reactionary in some respects, with Nazis seeing it as a corrupting more force, a cause of alienation from nature and a symptom of the decadence of modernity. But it was also embraced on the other as an important instrument through which to gain power in a war of racial domination. The reason why this form of ideology is right-wing is because it roots political legitimacy in a vision of nature (which a lot of conservative ideology does too, including all that contemporary neo-Darwinian stuff), and derives its utopian model for society on a certain view of nature (that is, it’s “given”: a system, likely hierarchical, to which humanity has to conform itself in order to live the best kind of life, rather than something that humanity can create freely.)
I agree about libertarianism, though: it’s can be difficult to make much sense of why its right-wing variety is right-wing, since it is in so many ways similar to liberalism. But I see it like this. Libertarians will often talk about natural law as the basis of authority, an intuitively it makes sense why the rest of their politics could be deduced from that insight: the tendency of government to expand and accumulate more power is seen as a potential infringement and encroachment upon the natural liberties and rights of individuals, and thus government must be kept at bay in order to preserve the rights of individuals that belong to them by nature. That’s different from a more voluntaristic conception of liberty and political legitimacy that one finds amongst liberals.
This doesn't contradict your point, but Marxists and Leninists, of course, are in some fundamental sense optimistic about the future. As with liberalism, there's a secular eschatology to these ideologies and a view of history that makes them fundamentally forward looking in their outlook. Here, though, the important qualification that I added in my last post was that these schools of thought are optimist about human nature, not, necessarily as man is, but as can is in potential. For these points of view, human nature is malleable on the basis of material and economic conditions. If human nature is rotten and corrupted by capitalism in the present, it can be reformed through a more just economic system based on a more thoroughgoing economic equality (which is where the utopian dimension comes in).
On the other hand, I'm not convinced that libertarian socialists are that pessimistic about human nature. It's difficult to square with both the anti-elitism of that ideology and the view that empowering people through direct democracy produces more benevolent societies. Libertarian socialists seem to think of government and power as inherently corrupt and corrupting, but it doesn't seem that they find ordinary people to be immoral. Still, obviously there’s a lot of other thought on the left, and plenty of exceptions to the generalization I put forward (which is why I said “in general”, after all).
I don’t think that’s entirely true. The summary of the left is reflected in a lot of prominent movements on the left: the identity left, the Democratic liberalism of the Obama era… even the utopian politics of Silicon Valley. If anything, the problem is that it’s too inclusive, not that it’s not inclusive enough. For example, that optimism about human nature is what undergirds a lot of American right-leaning foreign policy thought, including both Reagan-era anti-communism and Bush-era neoconservatism. It’s the ideology of American liberal internationalism, which has largely enjoyed bipartisan consensus since '45.