I actually can opine on his writings as I have read them.
His manifesto is pretty wholesome, in the true meaning of the word, not in the emotional reddit-interpretation.
He not only lays out all of his arguments but also all counterarguments.
What he says about this "misuse" argument is something like this:
The conservatives blame the leftists for the retardation of society, when actually a society can never uphold its traditions and values when technological progress happens as it reshifts the whole way the society works.
Also he states (which fits really well to the "just dont misuse it" point):
When a technology gets invented, not only can it be misused, it will be misused. The reason is that the technology always has a use and that use always gives an advantage. No matter how many governments say, dont (mis)use this technology, the technology has been developed so for it the timeline is endless. And one day, someone (think off china f.e. to get an edge on US Gov) will change his opinion and use this tech. Then everyone else will have to follow to be able to compete and soon it will be a necessity to use it.
His example in this case I think was gen-tech.
When youre able to make a fetus more healthy, smart and strong then itll be immoral to do so. Until china or korea does so. And sooner or later if you dont do it, your child is literally retarded in comparisson to everyone else.
You as an individual may have the choice to use or not use some tech. But society as a whole hasnt. And every tech comes with an advantage and disadvantage. And it always gives some freedoms here and takes some there. It makes the system go more smooth and create more money, but itll always reshape the society into something a little less natural for a human. Until we live in a completely unnatural world and psych illness will spike (yes he predicted that and thats where we are now).