Ah, it would have been easier if you'd started out saying "beyond the foreseeable state of the art" or "impossible". Then we could have discussed that issue.
However your appeal to authority (that authority being yourself) does not falsify what Drexler has said about this or his evidence.
And if you'd started out by saying "I think that full-on atomistic assembly nanotechnology isn't being taken sufficiently seriously by the scientific community" rather than "nanotechnology research has been suppressed for the past 25 years" then you'd have had a more sensible argument.
However your appeal to authority (that authority being yourself) does not falsify what Drexler has said about this or his evidence.