Is there any evidence that these paths are being cut? Mod communities for video games seem like they are thriving. Look at the sheer array of Minecraft mods, or mods for nearly any popular game on Steam.

Combine this with popular and easy game making software like RPGMaker, or even the ease that someone can set up a basic game on Unity. Beyond this, there are programs like Scratch and Processing that allow for fun and relatively easy computational tinkering.

I doubt the natural paths of curiosity have shrunk, though they may look different. Rather, the number of people using computers has massively increased, and the number of computer "tinkerers" is just a smaller proportion of people of the larger whole.