Because now, there are better alternatives.

If someone was too poor to afford a hoop and stick, I bet they wished they could have played with one, as a kid, even when they're fully grown. That doesn't mean, they would go out and buy a hoop and stick as an adult to play with, when ball in a cup is the current superior game. At the same time, someone who actually did play with the hoop and stick as a child, would probably prefer to play with that as an adult, even though the ball in a cup exists