That may well work on a site with a larger userbase than this one. In the past, even when we had significantly more members, it resulted in massive amounts of drama. It prompted people who were normally pretty relaxed to almost immediately step out of their pants and pull them over their heads while frothing from the mouth.
Discourse is basically a more Modern(tm) version of Simple Machines, I've seen it used for communities as small as two, and I honestly can't say I've seen the Like button cause drama. Similarly, while GitHub and Slack themselves might be large, an individual repo/team can vary wildly in size (from one-person repos to things like Bootstrap) and those are really just services for hosting your own community, not big monolithic communities.
Personally, I expect the non-anonymous Like button to cause more drama in
larger communities, because once you break 100 likes, it stops mattering that the names are all available because nobody's going to read them all. Then again, once you break 100 "I agree" comments, the thread has been killed.
So I'm going to go direct question:
Did the old Like system affect visibility, and was it anonymous?