This is really a straw man argument. If you go read Drexler's blog(e.g. this series: http://metamodern.com/2009/12/19/molecular-manufacturing-whe...), he is very explicit that the path forward is studying natural self-assembly from DNA and then tearing that apart, finding how it works, and modularizing/modifying it for our own purposes. None of this appears to be a "crazy idea" or something out of humanity's reach til long after we're all dead, as this author claims
Drexler's egotistical to be sure. It doesn't make him wrong
I think it attacks a Drexler that never existed; the chapter in Nanosystems on ways forward outlined similar ideas to that more recent post. Just because the bulk of Nanosystems explores a class of systems that's easier to analyze and currently impossible to build, he wasn't ever saying "Let's try to build this class of systems! Right now!" The OP was a total caricature.
Drexler's egotistical to be sure. It doesn't make him wrong