Maybe the title of the blog post was changed after its link was posted here? HN generally frowns upo submission titles that differ from the actual page title, and currently the page's title is "Being a good mentor – a developers guide".
There's nothing really in this article about mentorship being part of a career "exit strategy". So yes, the submission title is an odd choice, even aside from its nonsensical implication that one has to "age out" of coding.
It lowers the quality of the overall submission significantly. Shame on the OP.
Edit: I saw the OP is the author.
I think a little less of the piece now, sadly, as it’s pretty good.