Does he claim to be a hacker? I didn't see that in the article.
All I can tell, from your post and having a quick read of the article, is that for some reason you want to undermine the article, by questioning hacker credentials the author seems to have not actually claimed himself. Indeed, you appear to have made that criteria and designation up yourself.
So my question to you is: why do you want to undermine this man or / and his story?
All that aside, if you read the About page...
http://krebsonsecurity.com/about/
... certainly fits my idea of a "hacker".
"It wasn’t until 2001 — when my entire home network was overrun by a Chinese hacking group — that I became intensely interested in computer security. I had been monkeying with a default installation of Red Hat Linux (6.2) on an old Hewlett-Packard system, because for some reason I had it in my head that it would be fun to teach myself how to turn the spare computer into an oversized firewall [ah, the irony]. That is, until the Lion Worm came around and locked me out of my system. Twice."
"Monkeying"? Linux on an old machine? "turn the spare computer into an oversized firewall"? If thats not hacking, I don't know what is.
Am I now allowed to down vote your post, BTW?
No, of course not, if you had any intelligence whatsoever you would have already stated your case rather than down-voting.
(no, I'm not the downvoter.)