"Innovators" won general critical praise. A couple of reviews predicted
it would become the standard of the field. However, an evidently
knowledgeable review in IEEE Annals of the History of Computing faulted
it for peddling familiar potted legends without really digging for
deeper insight. Regarding Thompson and Ritchie, it looks more like
overt suppression.
Why not ask @WalterIsaacson on twitter. He was chairman & CEO
of CNN and managing editor of Time among other things so
presumably he is/was interested in facts.