I don't want to throw more shade at Schneier than needs to be thrown, but I want to point out that you've pointed out basically two† real credentials:

* He has a masters degree.

* He wrote a bunch of popular books, and reaped a lot of fame from them.

I work, part-time, in the cryptography space his best-known books cover. His most popular book, Applied Cryptography, is not well regarded in the field. Opinions differ on Cryptography Engineering --- I like it a lot --- but he's a coauthor on that book, alongside a practicing cryptographer of significant renown. The rest of those books are non-technical.

I've worked in security since the mid-1990s, and Schneier has been a presence in the industry that whole time. And his Mirai attribution is far from the dumbest thing he's had to say.

I want to be careful because I'm sure Schneier is very good at what he's good at. My concern is that in addition to that --- without intending to be --- he's also insidiously "famous for being famous", and that his takes on things like DDoS attribution are thus taken more seriously than they should be. There are HN commenters that I think have more reliable takes on what's happening in the computer underground than Schneier.

He should write HN comments rather than pieces that get syndicated into magazines. He'd be an excellent HN commenter. :)

† (You might add that he's a co-author of some well-known cipher and hash designs, and IIRC the sole author of Blowfish, his best-known design. [Don't use Blowfish.])