My son started riding when he was 13, went on a multi state tour at 14, came home and rode a century with a group of adults from a local club. At 16 he was the #5 junior racer in the US.
Get your son a bike with easier gearing! Doesn't have to be new, but he will enjoy the challenge a lot more. And the above poster is right. Most teens are great people. After 30 years of teaching mostly younger teens and raising 2 kids, I don't why people *expect* that kids are going to be awful at this stage. Mine were normally challenging, but fun. Teenage years much more enjoyable than babies to me...