is it the generalization you take issue with (i.e. the implication that reading of any kind in enough volume can teach critical thinking)? or do you actually take issue with the voracious readers of epistemology/philosophy of science/etc who are explicitly trying to use books as an aid to become more critical thinkers?
If anything they got the logic completely wrong. You are more likely to become a voracious reader if you have a propensity for critical thinking and curiosity.
