Couldn't it be said that the first edition of the Dragon Book is an indication of how far ahead of their time Aho and Ullman were at that point?
Hey something cool I found while googling - Holub's book is available as a free download from the author! (https://holub.com/compiler/)
The Dragon Book has flaws but it is also the case where the pioneer catches all the arrows. But the OP asked about unsubstantiated criticisms of the book so I added in the one I remember from my courses - mostly too much on parsing, not enough on everything else. The 2nd compiler course I took didn't even use a textbook, Dragon book or otherwise; it was a handful of papers and a semester-long project on SSA and associated documentation.