That is ignoring my point with a deflection. This isn’t 1999 with Linux as a (relative) newcomer and on the upswing, the adoption rate has clearly dropped over

That is ignoring my point with a deflection. This isn’t 1999 with Linux as a (relative) newcomer and on the upswing, the adoption rate has clearly dropped over time. I did miss the fact that Facebook uses Mercurial internally, but their public-facing repos are all on Github (including, ironically, their re-implementation of Mercurial, Mononoke). Open Source software doesn’t exist in a vacuum, it needs a community to support it and use it.