As someone that has tutored math and computer science, I don't agree with this. In my experience, people just don't think about problems the same way, which is why they have so much trouble with them. These people are teachable, but they will require lessons tailored to their mental strengths, which is often too much to ask when you're dealing with dozens of students. Those that are "wired" to think a certain way about math and its related sciences are just downright better at it.
Thinking about this brought back some memories of CS tutoring. The hardest part of tutoring is trying to provide good clues to help nudge someone along, but sometimes, it's really hard to give a good clue without being painfully obvious. ...and it's even worse when they still don't get it. I remember saying something along the lines of, "Now, we need to perform that action multiple times. What do we need to add to do that?" Loops. Stuff taught at the beginning of CS101.