Probably the same way people admire Marx. For all his faults, Marx very astutely observed some major flaws in the capitalist economic model. Such as the nature of Capital to consume its Productive Base like some maddened ouroboros. Marxist economic thinkers were the first to observe that paying workers shit and despoiling the land in the search of "more" eventually led to calamity. Nobody could afford the shit they were making, and the productive capacity of the land eventually fails. Meaning everyone gets to live in misery except the very elite of the elite who still have the means to hire men with guns to keep the Proles down.
The problem with Marx however is that his proposed solution, the "Dictatorship of the Proletariat" and no Private Property was a terrible solution to a very complex problem. Kaczynski was much the same way. His observation on over socialization, especially among Men were pretty bang on. As were his observations on how the removal of struggle in our day to day lives in favor of technological indolence makes for weak societies. Its not a particularly OLD idea however. Its called Decadence and human societies have struggled with it for a long time now. So in that respect he's just parroting stuff even the Roman philosophers bitched about in their decadent phase.
His proposed solution of triggering violent revolution and returning to nature was likewise incredibly off point. For one thing, the only way to enter that state would be a full on civilization failure like the Bronze Age Collapse, and there simply is no capability of that short of nuclear Armageddon. And since the elite power structures ostensibly needing to be overthrown control the nukes that is unlikely to occur. Any sort of revolution in todays age would simply mean elite replacement, rather then the end of civilization. Or even more likely, the revolt would fail (because the elites do have nukes) and the result would be even greater emphasis on putting the useless eaters in Pods or a Soma Coma.
I much preferred Frank Herberts ideas. Instead of returning to Monkey, we should return to Tradition. and Religion. Does not matter what Traditions or Religions either. Just have them. Believe them. And purge any heretics.