I don't buy into this logic. If you are able to intervene (i.e. suddenly take control of a large semi at its full kinetic energy in a life-critical situation), then you need skills of the same complexity as an existing truck driver. If you are not able to intervene in a tough situation, then the truck better be riding empty (with a procedure, for situations it can't resolve on its own, to stop and wait for support personnel to arrive on a car).
Yes, you do need those skills, but they are easier to put into someone off the street who has already spent years driving. People who have spent years flying are rare.
Training cycle for airline pilots is surprisingly short, less than a year if I'm not mistaken. It's just expensive because of all the gadgets involved.
