Unpopular opinion: I'm a top-poster. Important stuff comes at the top. No scrolling required. Everything else is optional. If you want, there's the history of that thread right below the important part. More recent stuff – the more important stuff – is near your current position, which happens to be near the top. Sure, if clients displayed the bottom of a mail right a way, we could have things in order. But: scroll down to read the rest of the mail, scroll up for its history? That'd be weird.