You may remember this chestnut:

[Tron (1982)] was disqualified from receiving an Academy Award nomination for special effects, because the Academy felt at the time that using computers was “cheating.”

I believe what we’re seeing now is a different branch on the same tree. Neill Blomkamp has an idea why performance capture artists may be seen as little more than glorified mimes:

We’re dealing with people from the last millennium. The industry is decades behind. Ten years from now, you’re going to have maybe one actor fitting into the realm of what they consider ‘normal.’