There is a difference between simple nostalgia and historical consciousness. Nostalgia is a emotional response, historical consciousness is something political philosophers argue about. But even for simple nostalgia, there is an aspect of it that critics often miss, which is that you can't be nostalgic if you don't think about the past. Nostalgia is a way for young people to gain experience without adding years.
Let's say, for example, that you "live in" the punk era. That means that you have likely learned all about it. Often the debate over nostalgia omits the fact that nostalgia requires familiarity with the past.
Political action is not the only form of action. I would argue that the nostalgia of contemporary music acts observed by writer Ben Beaumont-Thomas in Tuesday's London Guardian is more oriented towards establishing a separate economic sphere, rather then pushing for change through politics:
Just take a look at the names of the buzzy bands of the past few months: from the mountains (Mountain Man, Mount McKinley, Speck Mountain), through to the woods (Tall Firs, Woods), and then down to the sea (Beach House, Wavves, Surfer Blood, Best Coast, Beach Fossils, Coasting). There's a Rainbow Bridge to a Summer Camp, and Silk Flowers and Blue Roses in High Places. And all of it set utterly outside the city, outside work, outside the America of healthcare debates and ongoing wars.I would argue that the novel aspect of almost all of the bands mentioned above is the independent method of the production, distribution and consumption of their music. Assuming that Beaumont Thomas is advocating for some kind of politically involved message music, I would respond, "perhaps you should look at the methods by which consumers acquire small batch craft goods, and how that transaction can impact their relationship with other capitalist institutions. Perhaps the political answers we seek lies not in politics at all, but in our relationships with the institutions of consumer capitalism. That being the case, any comprehensive answer is going to include an emotional appeal to better times past. That's just a tactic of effective art, going back about a thousand years.
I don't know that a British writer can really understand the craft culture of American independent music. To ignore that culture misses the point I think.