His complaint is that if kg is the perfect unit of mass then make what we call the kg be the base unit and call that a gram instead. Makes perfect sense to me.
Of course this is an imperfect world. In a perfect world I'd like a meter chosen so that gravity is, to a good approximation, 1 m/s at sea level, and I'd like all of the units to be in base 12. (Easy divisibility by 3 is often very useful.) Including time, so that one doesn't have the awkward 3.6 factor converting from m/s to km/h. And our number system should also be base 12, and...I think you can see that I'm willing to complain about lots of things which will never change.
I want my number system to be in base 11 or some other prime number. You see: The vast majority of numbers are never going to evenly divide our base, no matter what base we choose. So we might as well go for a solution that minimizes the special cases.