I have no doubt that these aircraft had their foibles but suggesting that today's pilots would not be able to fly them....
IF taught properly, they would be able to fly 'em, but the training budgets would go out the window.
It would be interesting to watch a brand new F/O with low hours (as found today at many European air carriers) have a go...these folks adapt quite easily to a fancy FMS, but it should be remembered that they lack the necessary flying skills for these older jets and their handling problems.