Excellent points; "rigorous" would have been a better choice. I haven't yet had the time to study any computational fields, but I'm assuming the ones you list aren't built on the "fuzzy notions, and hand-waving" that Tao talks about.

I should also add I don't necessarily agree 100% with every in Lockhart's Lament; I do think, however, that he does an excellent job of identifying problems in how secondary school math is taught and does a better job than I could of contrasting "follow the instructions" math with "real" math to a lay person.