Hi clarephd,
my second supervisor was like that during my masters. In my first year I received 100 comments on an accepted manuscript. I am 3 and a half year in the PhD, and now I get less comments (only 36 comments in the last accepted manuscript). My supervisor is ALWAYS stricter than the reviewers.
I have also reduced the number of drafts: I used to go through 15 drafts per paper... now I think we go only through 4 or 5. So, I guess I am improving!
But yes, you need to work all the time and NEVER complain.