If I went to a party or a meetup where they asked to check my ID at the door I'd probably just walk out and never come back. I don't like parties run by the socially inept. Who asks their friends for an ID card? I'm willing to show my ID at bars and airports, to cops, and when opening bank accounts, because it's the law. And at least most of these venues have excuses -- banks want to link large amounts of your money…
No need to log in; it is possible, and always has been possible, to participate as a cookie-based user indefinitely.
We have some users that juggle cookie based accounts for as long as a year. And as of about 6 months ago we can reinstate your cookie on the "forgot my login" form, provided you gave us a valid email address to start with (we don't validate emails).