Well it's not really clear what he was hoping to modify in OSX that found impossible to change. Many of the settings mentioned are readily toggled off, you can install most linux software (Homebrew is necessary, i readily concede that without it OSX packaging is a problem), I'm not really sure what he wants apart from that. Not sure what he means by "developer workflow"...
Maybe it was more UI customization - there are definitely things which would be nice to tweak which are not tweakable, although there are a good range of apps and plist hacks to do so too. Mostly get the feeling he was primed to dislike it and, surprise surprise, disliked it.
I haven't given OS X a try yet, so I don't have the experience to know whether his rant is validated, but how about his example: using gcc. Is it difficult to get gcc running smoothly?
Maybe it was more UI customization - there are definitely things which would be nice to tweak which are not tweakable, although there are a good range of apps and plist hacks to do so too. Mostly get the feeling he was primed to dislike it and, surprise surprise, disliked it.