GitHub never would have had that problem in the first place if :+1: were not so easy to do. There's no reason to make emoji part of GitHub flavored markdown or for it to be an autocomplete.
There is now no longer a reason to make emoji as part of the markdown, as the vast majority of devices can now do it natively. When Github flavored markdown was first created, emojis were most certainly not at all widespread natively.
Not quite, it's difficult to avoid using votes as a heuristic for post quality. A reader's first impression of a heavily downvoted comment is negative. It encourages groupthink, downvoted comments are unacceptable, and serve as examples to others who might step out of line. Also, there is less pause when downvoting a comment if it is already well in the negative. When you think about it, the whole downvoting thing is antisocial. It's bizarre that almost every popular discussion platform these days allows users to passively shit on each other as a core feature.
In a system that doesn't rank, sort, hide, distinguish, or otherwise do anything other than increment a counter next to a post... huh?
Groupthink: You mean a community that downvotes a comment about X suddenly has a positive notion about X because the votes are hidden?
An example to others: I see this as a good thing - it lets an outsider get a good feel for what community members like. A number is much easier to parse than thousands of comments.
"Shitting on others" is a very melodramatic way of "people saying they don't like a comment with numbers".