Because big players (other than StackExchange) never adopted OpenID where you could paste in an arbitrary URL for your identity provider.
Also, OpenID probably shot itself in the foot by using a URL instead of something shaped like an email address, which would have allowed a zero-effort upgrade for the user if an email provider also wanted to offer OpenID.






I think it’s best we just maintain some recency bias when it comes to how harshly we judge people for their past internet behavior. If you were an asshole ten years ago and haven’t acted that way recently, I’ll just assume you were 12. We were all 12 once.