1. Just because a character is fine for one player, does not mean it's fine for all players and should be left alone. Sure, the PHB Ranger works fine for many players. But many players prefer some of the other published versions (personally, I like the version in BoHM).
2. This thread is part of the neverending cycle of "let's change this" and "it doesn't need to be changed." Both sides have a point, and you can't completely dismiss either. A lot of people say AD&D 1E was fine, and didn't need improving.
3. If you want to bring age into gaming, consider that an 11-year-old might have a very different playing style from an older player. Many classes might be fine for a kid that adults would find boring, and vice versa.
4. Mort already posted the primary problems cited with the Ranger, and the above statement addresses neither. The primary complaints are that it's too front-loaded, and that it does not do a good job or representing rangers of literature.