Frivolous, perhaps, but the shitty sexting apps and the like[1] are low hanging fruit where we can afford to be cutting edge. It's best to view the current Silicon Valley euphoria as a testbed for new technologies and labor processes and as an incubation chamber for the next generation working class. All the awesome stuff the writer wants will happen in the next decade or two, and most of the technologies and technologists involved will have their roots in the present frothy period.
It's also best to think comparatively: sure, maybe some capital is being allocated stupidly [2]. But lets compare to the second half of the 20th century and its great technological achievements. Technological development was uniformly directed toward the goals of state-building and war-waging. Given a choice between better sexting apps and barbarism, it's not even a real choice. One is clearly a significantly negative-sum game, and the other is neutral to mildly positive. We only ended up ahead after the 20th century through a combination of good luck and technology's tendency to adapt across domains and be used in novel ways.
[1] A minority of the start ups that actually exist, but let's grant it for the sake of argument.
[2] The article makes this entirely about the allocation of labor, even going so far as to imply it's character defects that cause workers to go work on stupid things instead of meaningful things. But fuck that noise: capital is the driving force here. I've never met an engineer who would prefer working on sexting apps to working on deep, fundamental problems. But our present system rewards capital for pursuing short-term profits at the expense of long-term economic growth. If you want that to change, fix the system. Hate the game, not the player.