Links don’t get previewed. It’s why many people copy paste from external sources instead of / in addition to linking. This is a blessing (never have to click on slow external link) and a curse (rare to ever clicks on links they’re too slow). If I just linked then nobody would click on it and I’d not get my point across. And I did t just want to copy the message since it wasn’t mine, so in place attribution as HN comment makes sense.