Yeah, honestly the only reason I submit to conferences now is because my advisor asks me to. If it was up to me I would submit exclusively to journals or just to arxiv/open review directly. I think I'll do this when I graduate (soon).

As for the reason why it happens in conferences, I think it may actually be a different set of reviewers. While journal reviewers are going to be conference reviewers, I don't think the other way around is true. I think conferences tend to just have a larger number of shitty reviewers (as well as more shitty submissions). And as you note, it is quite easy to misunderstand a work, doubly so when you're reading under a time constraint. It just makes for a noisy process, especially when reviewers view their job as to reject (not improve). I just think it is a bad system with a bad premise that can't really be fixed. For conference reviewing, I always try to write what would change my mind and if I think the authors should resubmit to another venue. But even reviewing I don't feel authors get a fair shot at responding. They can't address all my comments while addressing others in a single page.