I'm not even referring to voting in general, but the freedom and/or limitations imposed on it. Neither up/down votes should be limited (rather both, if at all), centralization encourages censorship and should be done away with for good as well as moderation (another word for censorship), "categories" (subreddits, subverses, whatever the fuck you want to call them) should be replaced entirely with user-controlled tags, spam prevention should be prioritized via instance authorization (a list of nodes that are allowed to be federated with), and editing/deletion needs to be network-wide (not instance only, which is pathetically broken).
All microblogging and social networking sites are using selectively flawed ideas and should be transformed. Nobody needs 'microblogging', they want socialization, and up/down votes aren't evil -- centralization is.