I think the author of this piece is correct. The thing that drives socialism and makes it impossible to kill is that people are unwilling to believe that life and humans not perfectable, that life has winners and losers, and that actual physical equality is impossible to enforce.
Or rather, socialism can't be killed because socialism appears to to our baser instincts and capitalism to our higher.
Also, as was pointed out, our tax system is such as the masses of lower income folks pay no taxes so have no hesitation to vote in high tax, socialistic spending programs.
Seems so many super rich folks are Dems or otherwise favor socialism. Why? A study of history shows that, as in the Russian revolution, the wealthy supporters were soon no longer wealthy, or even allowed to live.
I agree with your statement: "that people are unwilling to believe that life and humans not perfectable." See my signature.