I think getting an ATPL is a great achievement at any age, but this is just the media getting excited because this guy is younger than most. Why is he younger the most? Well, it's obviously because of the financial backing and the foot in the door that he received. Lucky guy.
But let's not forget the fact that studying almost any academic subject is easiest in your late teens: Your brain is able to absorb new information quicker (and remember it) far better than 10 or 20 years later. And don't forget that your reactions are at their best when you're around 20. It's therefore fairly obvious that the best time train to be a commercial pilot is your later teens and early twenties.
My only slight concern is that 19 years old is quite young to have so much responsibility, but presumeably the Airlines don't employ people who aren't up to the job.