Limiting login to these services makes sense - there's no point in signing up without an account to pull data from (one could argue that you could limit logins

Limiting login to these services makes sense - there's no point in signing up without an account to pull data from (one could argue that you could limit logins to Github / other code repositories explicitly) since the whole point of an account is to receive achievements for code you've written. I think the real problem is hiding the rest of the leaderboard past the top 10 behind a login, which seems awfully silly.