Missing from the list: it encourages group conversation and therefore pointless (and often damaging) flame wars where opinions differ. At one point or another s

Missing from the list: it encourages group conversation and therefore pointless (and often damaging) flame wars where opinions differ. At one point or another some otherwise decent human being starts using it as a platform to spread their particular brand of BS, be it opinions about programming languages / frameworks, past employers, social issues, their favorite (or disfavored) political candidate, and so on and so forth. Those being hot issues, people find it difficult to stay away, and it inevitably ends in tears. Signal to noise ratio ends up being abysmal, and the "productivity" tool ends up being very counterproductive. That's why I turned off Slack at one point and told people that we're in the same building, and if they need to urgently talk to me, they can just stop by my desk, and if things can wait for a few hours, send me an email. Easy.