* is a special character on HN and can cause unusual formatting problems, and especially in a code context can be easily confused with the multiplication operator, and attempting to represent a footnote-superscript asterisk character requires use of ZWJ and "combining asterisk above" and hoping that it's supported ⃰. The 'second footnote' character is a reliable indicator of the presence of a footnote and is not easily confused for the addition operator. You're correct about the etymology of it, but attempting to force adherence to a historical use (that is not prohibited by the site guidelines) is no more likely to succeed than asking a language to stop changing is.

⃰ And that it's even remotely readable to be an asterisk, which my terrible vision can't make out in the text input field on HN, and that it's wrapped correctly (which it's not), and that it's spaced far enough away from the previous character (which it's not) and that <SPACE> <ZWJ> <COMBINING ASTERISK ABOVE> are handled properly by the website (which is still not universal† yet‡).

† Emoji have helped, though HN specifically removes them.

‡ Note, however, that in the HN text input field, the dagger and double dagger are not shown superscript, as they are in the resulting comment you're reading now. It seems to be up to the font to decide what to do, as Unicode opted out of superscripting concerns.