OS X has been around for 21 years. Many readers of hacker news aren’t that old yet.
Triple click is only a thing on iOS, apparently. Thank you for the correction: https://support.apple.com/en-us/HT204390
Double click is easy to teach but it’s sure as hell not discoverable. Whereas second and middle button advocates have, to me, semi convincingly claimed that they could also be taught through consistent application. In other words, not better but not worse.