I'd think the best would be a mix of both.

I totally agree. If people want to complain that there are not enough female software developers, then start at the source, not the editorial page.

Give young girls role models that are not exclusively pink loving homemakers. This is one of the first notable steps in this directions I've seen and I applaud it.

I'm not sure what this even means. Are you saying there isn't room for efforts like 1) pushing for better recruiting practices 2) teaching grown women to code?

There's certainly a case for both approaches though this one is probably most effective in making long lasting changes.