People often ask why I contribute to open source projects or otherwise work on building automated tooling. They see me spending hours to automate a task or fix a bug that take seconds to do or avoid manually, in a way that the original XKCD comic says won't pay off. The disconnect seems to be that the comic and those people only consider time it saves me, not time it saves the tens to thousands to millions of other people who will use the script or patch or whatever when I publish it. So, here's a version of xkcd.com/1205 updated for making decisions that benefit a thousand people instead of just one.
If you are having recurring conversations with everyone you know (... and apparently many you don't?) about spending too much time "making small contributions"... you probably need better time management skills.
And yeah. That is pretty much what I assume happened. You made a comment about how you spent twelve hours optimizing the way you read your email. Someone jokingly pasted an xkcd comic. You went "well ackshually" and decided you would argue that you are saving the world by saving everyone else time and blah blah blah.
Which is how most of these go. Because people either seem to realize they are supposed to laugh along with xkcd in a "Well... uhm... Okay, you aren't wrong but.. I got nothing" kind of way or they laugh until they feel "called out" and get set off.
How did you get from "People often ask" to "having recurring conversations with everyone you know"?