It's a rebuttal to "A sane format would pick one.". This is an explanation of why PSD is not insane. The primary point is that the use cases and expected users are not what our ranting developer might have liked.
It also rebuts the idea that Adobe makes people "sign[] in blood" for specs.
On both counts, whether you consider it adequate is up to you. Personally, I've been involved in enough stuff that the format makes some sense to me (reverse compatibility in a binary format means you make crazy choices by any other standard), but I'm somewhat unconvinced by the second one. If all it takes to get the specs is a fax, you might as well at least turn that into an email, or just put them up on the web... but that's just my opinion.