What is up with this insistence of certain bloggers to require non-anonymous
commenters?

I was once again reminded of this curious obsession while reading Geert’s
comment on his own blog:

No, I delete posts from "No one" <noone@email.com>. If you can’t be troubled
to at least make yourself look human, I can’t be troubled to give you an answer.

but he’s certainly not the only offender.

It’s very simple:  either you allow people to post with a default (e.g.
noone@email.com) email address, or you just don’t
let them post in the first place.  Letting them post and then deleting
their post just because they didn’t feel the need to type a bogus email address
is just plain ridiculous, and a waste of time both for you and for the poster. 
Especially if you didn’t even bother spelling out the rules you follow to decide
whether a comment is worthy of your blog or not.

I actually even question the attitude in the first place.  Tell people that
they need to submit a real name and not an anonymous one and they will either
stop posting comments on your blog or sign them John Smith.  And what have
you gained, really?

Stop judging people on their identities to avoid addressing what they write. 
This is the Internet.  Deal with it.

Update:  the original poster addressed this very point by posting his
next comment under Geert’s own identity.  I rest my case :-)