Maybe because the first line on the page you linked reads: > Tip: App Passwords aren’t recommended and are unnecessary in most cases. To help keep your account

Maybe because the first line on the page you linked reads: > Tip: App Passwords aren’t recommended and are unnecessary in most cases. To help keep your account secure, use "Sign in with Google" to connect apps to your Google Account. So, for Google, App Passwords are clearly "second class citizens", deemed insecure and not recommended. And, as an app developer, you probably don't want to be seen as recommending an insecure authentication method?