GitHub accounts are a virtual pre-requisite for a developer at any startup nowadays. Many developers are working on things in private repos and maybe don't have a ton of public activity to display. We offer them the option to connect their full account so that we can parse their activities to show that they are, in fact, active and building things.
Note that we also offer the ability to connect to what is already publicly visible via GitHub if you don't want to grant us full access.
It's definitely not always true, for sure, but in our experience and with the companies we've worked with, almost unanimously their first comment was always, "Man, it'd be cool if I could see a breakdown of their GitHub data, too." (of course, before we implemented this feature). It's not for everyone and definitely is not the end-all-be-all of what makes a good developer, but many startups today like to see open-source contributions.
A GitHub focus on a job site attracts employers who rely on that. I've always deliberately avoided GitHub, so job sites that give it focus aren't for me, because the employers are looking at different metrics than what I have.
Your reasoning makes sense, and it's perfectly fine to do it the way you are. I think people like me are just pointing out that this makes us self-exclude ourselves from the site, in case you wanted us.
With a quick experiment (nice site btw) I see that it only seems to look back 3 days or so for commit totals to a private repo. If you are looking for anon aggregate data, to prove at least some activity then I was expecting longer?
Edit: As a follow-up, how do I remove a github reference once it was set up? I couldn't find it in the update options :)
We actually pull your most recent 30 actions, both public and private (if you connect a full account, public only obviously if you connect your public account), which is to say, we only hit the API for one page of activity data. All that means is that you've been particularly active :) There should be a timeframe there to give you context. The last 30 actions in the last three days indicates a lot more activity than the last 30 actions in the last 200 days, for instance.
As for removing GitHub, that's a good catch. We should provide a way for the user to _detach_ their accounts as well as indicate that they don't have said accounts.
Note that we also offer the ability to connect to what is already publicly visible via GitHub if you don't want to grant us full access.