Not quite what the article talks about, but Accelerationism in communist/anarchist thought is the notion that you either permit capitalism to go off the rails without hindering it or even encourage it actively. The goal is to "show it for what it really is" and make things so unpalatable that a worker uprising is inevitable (or at least more likely).
So in that view, an accelerationist could be a socialist who opposes things like minimum wage, universal health care, privacy rights legislation, etc.
I am a Socialist myself and I often talk with people who are accelerationists; I am divided on the issue personally. Accelerationism in the Communist sphere tends to align itself with policies against working within the democratic system to improve conditions, as you noticed even to reject social democratic policies. The other argument for this from their point of view is that it would encourage complacency of the workers to be having these social democratic policies, as some view Keynesianism did to the Western capitalist nations.
An interesting point here is about Marx himself; he wrote:
"Moreover, the protectionist system is nothing but a means of establishing large-scale industry in any given country, that is to say, of making it dependent upon the world market, and from the moment that dependence upon the world market is established, there is already more or less dependence upon free trade. Besides this, the protective system helps to develop free competition within a country. Hence we see that in countries where the bourgeoisie is beginning to make itself felt as a class, in Germany for example, it makes great efforts to obtain protective duties. They serve the bourgeoisie as weapons against feudalism and absolute government, as a means for the concentration of its own powers and for the realization of free trade within the same country.
"But, in general, the protective system of our day is conservative, while the free trade system is destructive. It breaks up old nationalities and pushes the antagonism of the proletariat and the bourgeoisie to the extreme point. In a word, the free trade system hastens the social revolution. It is in this revolutionary sense alone, gentlemen, that I vote in favor of free trade." (Emphasis mine)
The problem with that kind of acceleration is that it assumes that the problem with establishing change is getting people to believe that their life sucks. But that's not the problem, the problem is convincing people that action for change can make things better. Concrete victories, starting small, can do that; letting things get worse doesn't.
Capitalism replaced feudalism because the bourgeoisie took power, one small victory at a time, from the feudal nobility.
If a system in which the working classes take power from the capitalists is to replace capitalism—and the modern mixed economy may be a transitional form on the route to such a system, or might just be a diversion—then it's going to be the same way.
>I am a Socialist myself and I often talk with people who are accelerationists; I am divided on the issue personally.
By the time working people are miserable enough to unite and rebel it will already be too late. The rich and powerful will have the logistics and technology on their side to quash any rebellion handily. Social Democracy is the only way forward. The people on the bottom need to have the capacity to resist and you can only do that by keeping the relative power of each segment of society at rough parity so nobody can exercise dominance over another.
The trouble with an accelerationist viewpoint is that even if the system collapses what comes out of the ashes won't be enlightened advancement and revolution, it will be a general regression into warlordism and feudalism. Even if Lefties win those fights you won't get anything like a Socialist society on the other side of it. The skill sets and temperament required to consolidate power among sociopathic warlords are not the skills sets or temperament you need to establish a just and egalitarian society. Quite the opposite, as you see by any country where communist insurgencies actually wind up in charge.
So in that view, an accelerationist could be a socialist who opposes things like minimum wage, universal health care, privacy rights legislation, etc.