- it makes authors think more before posting; if there are typos, or it isn’t exactly what they want to say, and it gains traction, they can’t fix it, so they work to make it right the first time
- Most people ignore edit histories [citation needed; based on my own experience and knowledge of others’]. As a result, if the post is edited, the conversation can get fragmented and confusing for later readers
That said, I’d love it if there were a way to see deleted tweets, at least of politicians