I have to be honest: the fact this is in "things not to read" from ISO is one of the strongest endorsements I could imagine. For that to happen, it must both be successful enough to get on their radar, and also to tick them off.
That said, I know why this is on the list. Zed honestly doesn't like C, by which I mean that he recommends a lot of things that are (in my opinion) genuinely best-practice, but fly in the face of either historical norms, or the techniques that the ISO C team wants to push. Depending on what you're aiming for, this might indeed make it a bad work—but it can also make it a great one. I'd liken it in some sense to DJB's projects: Zed recommends a fairly unorthodox, but (again, in my opinion) excellent way of writing C. If you need to interface with people who write C the way most people write C—you're working on an operating system, perhaps, or a legacy codebase—this may be a problem. If you're writing C because you need to write a few components of your project in C for performance or [lack of] abstraction reasons, and would prefer not to hate yourself later, it's great.
The problem here is that Schildt's books really aren't good.
But as far as LCTHW goes: I doubt very much its author has the same objectives for writing a book about C that the standards weenies do, and I doubt very much that they took that into account before warding people away from the book.
It's not ISO: that's from Freenode ##c. It's likely they just hate it because Zed got a trivial detail about the C standard slightly wrong, rather than because they're trying to persecute him or something. It's more their style. Zed's the one who's more likely to be persecuting someone.
Someone who would ding one of the two best MTAs ever written (the other of which inherited its design from qmail's) because of its indentation and variable naming style says more about themselves than about qmail.
Someone who considers Qmail one of two best MTAs ever says more about
themselves than about Qmail. If it was that good, why would it effectively
die? Virtually nobody uses Qmail anymore.
Not to mention that Qmail is (well, was at some point) one of two biggest
sources of wild workarounds in all the other MTAs, the other being MS
Exchange. DJB took standards and implemented their subset that suited him.
http://www.iso-9899.info/wiki/Main_Page#Stuff_that_should_be...
"Too many factual problems and a presentation that gets you to do things wrongly before being shown how to do it correctly, and not even always then."