It's possible to express dissatisfaction with a title and to encourage better posting habits without being a jerk. I agree with your summary.
The problem isn't with HN being jerks to young people. The problem is with HN being jerks to anyone.
The main problem I think we have is that posts will continue to be 'link-baity' and some of those will be related to age. Each time one of these hits the front page the community will need to respond to it, and for the near future that response seems likely to be a reignition of this debate.
How do we educate 'drive-by-posters' who create an account simply to post an article (potentially with a link-bait title)? Is it up to moderators to change the title? Users to flag it? Should we just keep arguing about age in post titles?
I don't know the answer, but I think reasonable application of the posting guidelines is appropriate, and for me that means keeping the post title as relevant as possible. Most of the time, the age of the poster/developer is not relevant enough to be in the post title.