That's kind of the point of the article, materials do not behave on a nano scale the same way they behave at our macro scale. You absolutely cannot scale down, you have to design from the bottom up instead.
The author thinks this is impossible because progress is slow. That's not really an argument, but I'll agree that "just you wait and see!" isn't one either.
However, biology shows us that it's not impossible to do self-replicating "machinery" so I think we'll get there one day, but it might probably be a lot more organic and a lot less mechanical than we currently envision when we say nanotech.
The author thinks this is impossible because progress is slow. That's not really an argument, but I'll agree that "just you wait and see!" isn't one either.
However, biology shows us that it's not impossible to do self-replicating "machinery" so I think we'll get there one day, but it might probably be a lot more organic and a lot less mechanical than we currently envision when we say nanotech.