A point of principle: it is a good idea not to open your mouth if you have nothing intelligent to say. Asking a question is intelligent, so no blame in that. Answering a question stupidly, though, is a sin from which something can be learned: to remain quiet.
Saint-Saens, the author of probably the two most perfect, beautiful and vivacious piano concerti (I mean 2 and 4), the daring author of Sampson et Dalila, the Carnival of Animals and the Danse Macabre, the irrestible spirit behind the organ symphony, cannot be called anything but genius, master, great gifter of music for all nations and generations.
Prolific, yes. Sometimes not very selective, also true. Composed as easily as an apple tree gives apples, true. You certain cannot blame him for lacking the obsessions that lead the geniuses of Dukas, Brahms and Chausson, to name a few, to destroy 90% of what they wrote, and those of Beethoven, Mahler and Prokofiev to rework each measure 10,000 times.
Saint-Saens, by the way, was the teacher of the likes of Godowsky, Faure, Debussy and Ravel; the first modern scholar to edit the works of Rameau and Couperin, and a proficient aficionado to math and astronomy.
A silly book may think this is dull. I think the book is dull. Get some music and judge for yourself. Say, for example, the bassoon sonata, the left hand etudes, his christmas oratorio and the third violin concerto. You will discover champagne.