Trump certainly does lack the legitimacy steaming from the popular vote win, while still being legally elected per archaic but still existing stystem.
Comparing a number of pieces left with a number of votes casted by actual people is quite hyperbolic.
Trump got much less votes than his opponent. I don't think anybody can dispute this. There's something weird, at best, to call one country's democratic, and yet have a system under which a man with less support becomes President. Trump has no popular mandate.
Of course, as I've been saying in other threads, you don't get to change rules during the game and he's legally President-elect. Doesn't mean we have to approve the system.