I fail to see the "complaining" side in all of this. I interpreted the question as "what's the meaning behind 'm_'?". Until I read your comment, it didn't occur to me to see it in a complaining light, also because I imagine the question would have been worded differently in that case (e.g. "why m_ instead of <something_else>?").

And judging by other comments to the question, I wasn't alone, luckily.

This is the often case where some HN downvotes you to heck and the next hour bunch shoots you up to the moon. There is pretty much no predictability and it all depends on whether your responder makes a good case.