It's not pg's job to equalize the gender ratio in programming, nor is it his job to get girls interested in it. Saying he thinks you need to reach girls young does not obligate him to go research what organizations are out there doing just that.

He meant the post to be a statement of his position, not a rallying cry to fix a societal problem. You seem to have wanted the latter, not the former. That's fine, but it's not a failing on his part that he didn't write the post you wanted him to write.