Because most of it is circa 1998 Slashdot-esque content which really isn't constructive and only damages what little faith people have in this industry even further. The article itself is vitriol.
Not only that, the site is designed to intentionally hide the author obviously because being accountable for an opinion is probably bad for them in this case.
So your logic is: "This guy has database opinions I don't like, and he has gotten some facts wrong, so he ought to put his real identity and address on the Internet for all to see?" I mean, what? I'll take Slashdot-style open source zealotry over something that smells a little bit like 4chan-style threats of "doxxing," thanks very much.
Signing your opinion with your nick or name has nothing to do with doxing. It's not like we're talking about his address and SSN. But if you don't like the word "vitriol", use "FUD" instead, because that's what it is. There are lots of things about MS SQL one could point out and say: hey, this is broken. But the vast number of statements on that page are empty, misleading or simply untrue.
That being said, I don't think this site is that harmful. People who'd eat this content up won't read it (tl;dr) and people who do read it will most likely have their own opinion anyway. It's not an authoritative source people tend to trust like, say, Wikipedia, so I'm not bothered about it personally.
I can definitely see why you'd say this, since the original parent comment was quickly deleted and you presumably didn't see it.
The original (now flagkilled) parent comment by that poster contained some information regarding the author's place of residence. I (and others) felt this was well over the line.
There are many reasons not to freely give out your address, or name for that matter. The validity of ideas need not be tied to an identity. If an idea can stand on its own, then so be it. If not, you can just move on.
"...being accountable for an opinion is probably bad for them in this case." Same for you as well, it seems.
Not only that, the site is designed to intentionally hide the author obviously because being accountable for an opinion is probably bad for them in this case.