For such a "classic" book, I was gravely frustrated. I have never read a cartoon book that was a chore to finish.
Well, first the book is overwhelmingly leaned toward foreign silent animation. Now, it would sound nationalistic to say that American cartoons were the dominant one in this era, but notice that every Philistine knows Felix the Cat, not Stromlinien. There's a reason. This is not to damn European animation, but in the old days it was the U.S. animation business that dominated everything (nowadays, Japan is the great country of animation). Anyway, German and truckloads of French animation being the big focus is inappropriate and just the author's obsession and bias.
The author worships Emile Cohl tremendously, and this bias leads to virtually everyone else getting the boot. Bray, Disney, Lantz, Terry, and so on get squeezed in a few short chapters.
Donald's Francophilia gets the better of him, sometimes: he claims that Winsor McCay stole stuff from a French movie called La Repas de Bebé, which seems like a stretch. I doubt highly he was watching French stuff.
His focus on silent cartoons shows that he only cares about them, so his opinions on the sound stuff come through with odd sayings, like his accusation that the Dinky Doodles are better than sound Lantz films.
Donald's anti-Disney viewpoint is irritating. You can tell from his tone that he is convinced that Walt is overrated. Oddly, he actually believes that Charles Mintz created Oswald. Presumably, he knows nothing about Charles Mintz. The reason for all this might be because he lists Richard Schickel's The Disney Version as a source, a book notorious for its hateful rhetroric. Tellingly, in the Felix chapter, the epigraph is an Otto Messmer quote: "To me a mouse is repulsive thing."
His Felix chapter suddenly delves into pseudo-intellectual nonsense in an otherwise straightfoward book, talking about him as a "insurrectionist" and "outsider", and observations like "Felix's allegory of self-creation is emblematic of the animator's creation of the cat out of the elemental materials of ink and paper." Dude, they're just cartoons!
What keeps this from an F is that it isn't worthless, with many interviews conducted with Otto Messmer, Friz Freleng, Shamus Culhane, and others (sadly, Dick Huemer had passed away before Donald could get to him). But otherwise a big letdown.