I don't think that article is very fair to nathan robinson. The article never really implicates that he inconsistent with libertarian socialism, rather he is inconsistent with some of the early anarchist thinkers like rudolph rocker and emma goldman. It tries to implicate he is inconsistent with libertarian socialism because robinson supports a new deal democrat politician, and that this method of electoral politics always fails to acheive libertarian socialism.
Well to be clear, bernie calls himself a socialist and isn't one-because he does not support democratic control over the means of production, and that's what socialism is, and was when workers conceived of it in the early 19th century. The goal of 1930's social democrats was to 'save capitalism', as john maynard keynes put it. But at the same time these elections had socialists supporting them, and really the power of these politicians is highly dependent on how powerful the working class want themselves to be, and their goals are dependent on that as well. If the working class was largely libertarian socialist, then they could easily elect one to power. In my personal view, electoral politics is a tool where you can acheive some policy change. It's something the working class can use in their favour, with any goal in mind be it social democratic or libertarian socialism, and this kind of tool is not something you have the priveledge of using in dictatorships/totalitarian governments. And that the effectiveness of electoral politics really just depends on the power of those that are trying to use this tool. Remember that corporate power itself has acheived it's massive rise in power in large part through the electoral system. It can go both ways imo. It's not set in stone that elections have to be completely dominated by money as political influence, in my view that corporate lobbying system is very fragile.
The point made near the end of the article about social democratic politicians being elected to power hasn't worked because they have led to austerity, or been compromised. I think that's just because social movements have stagnated, they didn't maintain their antagonism towards the capitalist class. And libertarian socialists have not really acheived their ends with any methods, not just electoral politics. Not because their political systems didn't work, but because of the enourmous opposition from the major centres of power in the world.