As someone who learned QBASIC at the age of 8 I take offense to this statement. It took me 10 long years to break out of BASIC thinking, but it certainly did not mentally mutilate me.
Take it up with Dijkstra. I learned QBasic at around the same age, as well, and I don't feel impaired either---though Scheme certainly changed things at around age 14. I'm sure he was talking about Other People.