This is a long essay, so right now I'll just respond to a few points.
(1) Cultural Revolution. This is a very complicated topic, with much more nuance than either ultras or ML's give it. But to speak very broadly, the problem isn't that it mobilized the people to do nasty things to the bourgeoisie; the problem is that it was voluntarist and anarchistic. Hurting and shaming the bourgeoisie is a worthy goal, but it accomplishes nothing if it isn't accompanied by a real increase in people's living standards. The tendency of late Mao, and even more, of the Gang of Four, was to think that communism could be built simply by instilling in people the right ideology; which is idealist rather than materialist, for ideology is a function of material conditions. Thus Deng's corrective, "socialism is not poverty," was desperately needed. One can argue that Deng went to far, and ultimately fell into right deviation. But we should not allow this to obscure the fact that Gang of Four were massively left-deviant, and that Deng's occasional rightism was simply the inevitable reaction. Thus, if China during the 1990s came dangerously close to neoliberalism, it was ultimately the fault, not of Deng, but of the Gang of Four.
The DPRK, by the way, does uphold a cultural revolution -- it is an integral part of the Three Fronts theory, so the writer of this article is wrong again. The difference is that here the cultural revolution is ongoing process, proceeding alongside economic development and gradually transforming the whole of society. It is planned, rather than voluntaristic. And this brings us to the central problem with "Maoism" and all forms of ultraleftism. Processes need to be guided; you cannot simply hand people guns and assume good things will happen.
(2) On "Vladimir-Fucking-Putin." The author finds it odd that MLs give critical support to the Russian Federation in its fight against Ukrainian Nazis, but not to the Shining Path in its struggle against the Fujimori and his goons. The difference is this: Putin, by stomping the Ukro-Nazis, is actually performing a useful service. What Gonzalo did was the reverse of useful: it alienated the masses, and drove people who otherwise might have sympathized with socialism straight into the arms of the Fujimori regime. There is a reason that many Peruvian leftists today believe (in the face of any real evidence) that the Shining Path was a CIA op. Which brings us to --
(3) Gonzalo was violent, but so were the Bolsheviks. The implied "goodness" of violence smacks of anarchism, or of Georges Sorel. As Marxists, we are not for violence; we merely recognize its occasional necessity. We don't do the fascist thing of walking around and advocating violence for its own sake; that is adolescent. We would all prefer a peaceful transition to socialism; the problem is that the bourgeoisie never lets it happen. We advocate, not violence as such, but the right of people to defend themselves by any means necessary. If some Gonzaloite can explain to me how killing pregnant women and scalding peasants to death constitutes necessary and appropriate revolutionary violence, I'll gladly become an ultra; but until then, I'll keep thinking of the Shining Path as basically Azov with a red flag.
(4) Why don't AES states export revolution anymore? The DPRK does, in a limited way; obviously it can't do much given present circumstances, but they do give what aid they can to revolutionary movements around the world. The question really comes down to: Why doesn't China export revolution?
The flippant answer is that we should be grateful China doesn't; after all, their attempts to export revolution during the 1970s led to some of the strangest foreign policy the world has ever seen. The serious answer is this. Global capitalism is in its last, decadent stage: accumulation through destruction. No longer able to produce real wealth, the bourgeoisie create wealth in the imperial core by destroying it elsewhere. Thus, it is imperialism that now must export revolution in order to survive. To uphold stability, and global trade, in the face of never-ending destruction is now, ironically, the revolutionary position.