I understand the sentiment of trying to build a more positive oriented community by getting rid of something like downvotes. However, that feels almost exactly like what Youtube did in removing dislikes on their site, which was widely unpopular. It's a great indicator of spam or other undesirable content and removing it altogether might be doing more harm than good.
Plus, if filtering becomes a thing, being able to, for example, ignore posts with less than 5 upvotes would do wonders for some browsing once the site gains more traffic.
That said, I will always advocate for options. If that became a setting in a menu somewhere, I think that could be the best of both worlds.