I KNOW THIS ONE AND THE ANSWER IS : IT"S MICROSOFT'S FAULT.
Back in the day when Email first became popular, it was normal and accepted use to do "in-line-quoting". You would hit "reply" and get the text of the original mail with a quote character, mostly ">" in the begining of the line. Then you would put some empty lines at the point where you wanted to answer/comment and type your reply in the middle of the email you received, easily giving context to your words, and making it obvious to what this comment relates, while also showing which part was by the sender and which by you (due to the quotation symbols)
This was a very good system, and then came MICROSOFT OUTLOOK
and they defaulted to giving you a empty page when clicking reply and just dumping the whole mail you replied to somewhere below, out of sight.
everyone using Outlook started "top-posting" to the annoyance of every intelligent being in the galaxy, but because Outlook was the first email experience many people had, the culture of in-line-quoting was destroyed by the unwashed microsoft masses.
fast-forward to today, where a young person (that is below 50) posts about a topic just to vent, and a old person (over 9000) replies with a sincere history lessen from a time where even email were better.
yours truely,
someone who is still salty about that and just decided to make a youtube rant about it.
I said I **will **make one, and as soon as I **did ** i will post the link (*)
(*) as a person with ADHD, the chances of both those things happening before the heat death of the universe indistinguishable from zero.