Due to the recent low-quality posts on U&L, I've asked the Community Managers to disable unregistered participation on our site. They have recently enacted that change. Hopefully this encourages positive participation and isn't too much of a hurdle for earnest participants in our community.
Update on 2023-07-07: this change (enacted May 29th) has prevented further low-quality posts, and -- at a glance -- has not seemed to create much of a hurdle to participation. I grabbed a screenshot of the site analytics for the past 2+ months; here's the chart of posts (questions + answers):