Because it interrupts the flow completely when they could have just written the model number along inside of the already-used parens like a normal human being.

Because it interrupts the flow completely when they could have just written the model number along inside of the already-used parens like a normal human being. With a screen reader, it'll get to the superscript 0, read that out, and then won't be able to read the actual footnote content until the very end. Can't jump around like our eyes can. "⓪" isn't even read by a screen reader (at least not narrator on windows 10). Footnotes in internet comments are useless and unnecessary anyway.