A lot of posts are from bots. It would be cool if the bots could make a whole new submission and not link back, but all things considered I'm just happy there is interesting content.
For some types of posts that's fine - the capybara community, for instance, is a steady stream of capybaras from reddit (I think) and that's not the type of post that needs interaction with OP or comments. Posts from say, tech support, very inappropriate to copy to Lemmy imo without a link back and an explanation as it might get a conversation going but it also confuses people who think their response might be seen by the OP.
Since it can't be used as a gatekeep like in reddit, less than worthless, but people's ego still crave it and they crumble when their content goes negative (ask the people at lemmynsfw)