I remember when this was new and I've never found it as amusing as other people seem to. It's super easy to shit on software that's almost 50 years old. But where's the replacement? Windows is still worse as a web server platform than various Unix descendants (Linux and BSD) despite Microsoft's best efforts, and it's not free. Unix has its flaws but being a "Unix hater" is just dumb.
UHH absolutely does not attack UNIX for being old. See "Who We Are" in the preface. The authors worked with systems they felt were superior in many ways, until industry/economic forces pushed them to UNIX. "This book is about people who are in abusive relationships with UNIX, woven around the threads in the UNIX-HATERS mailing list." They're not a bunch of angry outsiders, they're UNIX insiders who reject the idea of…
Anyway, I'm not gonna rehash the same old arguments with you.