The reason why is really quite simple. There's no fun left in it. Chess has become a thing of memorization more than random chance or instinct. Anyone who continues to play chess probably knows the name behind some of the opening moves. None of which I do, and I really don't care. To put it more simply, playing a game of it against someone feels like it becomes a battle of who is smarter, yet really only tests your ability to match patterns to memory.
My dad never tried to teach me the names of the moves or the patterns behind them. He explained the basic rules and away we went. It was fun then, but not anymore.