I turned off anonymous comments about 18 months ago due to the high volume of spam that was getting through. I didn't have time to monitor 100-plus garbage comments per day. If I checked them from my phone, one always got by me. Then I'd spend an hour or so when I got good signal going through the approved comments one by one to get rid of the garbage.
So I turned off anonymous comments, thinking the sudden explosion of spam would eventually be managed by Blogger's sharp eyes.
I recently turned anonymous comments back on to see what would happen. After just 12 hours, only one spam comment had come through! I assumed Blogger had fixed the problem, and I was tickled!
But then I checked the spam folder.
62 spam comments in 12 hours. That's about five an hour. True, at least Blogger is catching them in the spam net. But holy moly!
There were two valid comment in there with all the muck.
So I turned off anonymous comments again. It means questions about snowflakes aren't as easy for less-experienced computer users, and I apologize for that. I moderate all comments because when you have a popular blog, jerks find a way to get through, even when you are taking every precaution. That means I have to spend time making sure my blog is safe for anyone who might be perusing and clicking links.
So if it's more difficult and time-consuming to type in an email address or log into Ravelry to ask pattern questions, just think about how much time it takes one person to review every single comment and sometimes even every single link to make sure no rubbish gets through.
Plus, email or logging into Ravelry is SO much better than word or number verification...