The problem for "interesting" people is discussing those topics with you or me, isn't that interesting to them. That's the problem with discussion forums - I'd find discussing Linux with Torvaldes fascinating, but his side of the conversation wouldn't help him solve his problems or forge new ground. It wouldn't just be a waste of his time but it would be boring.
I've seen all of those topics you mention gain traction, probably with the exception of "climbing the career ladder at big corp", but that's the broader Zeitgeist not just HN.
The way to get more C++/Fortran/Java discussion on HN is to submit good relevant content. If you post something really really good, sometimes the James Gosling of X shows up to comment because HN's diversity keeps them around. But any really good topic is likely to draw comments from people who worked with the James Gosling of X because HN has a lot of those people.
HN has grown large enough that there is an audience for just about any tech topic so long as the resource is reasonably good...in fact, that's been the case for a long time, and this from someone who was posting articles about Windows and Microsoft in the days where every time the Macbook got a new 8% faster Core 2, the front page of HN was dominated by the press release and Ask HN was full of "are you upgrading?" treads.
In the end, finding or creating good content is the way to increase discussion of the topics one finds interesting and to influence the direction of the community.