My interpretation of the graph is this:

Overall, things that rank high on SO and low on GH are more "corporate-y". Things that rank high on GH but lower than the line are "startup-y".

We have some ask HN questions like which tool I should pick-up, employable skillset, etc. Purely based on this graph, I would say pick the top-right points that lie close to the line. That should strike a decent balance.