Linux Became Useful Quickly
Aside from an enjoyable way to experiment with operating system
programming, Linux quickly became a very useful tool for general
computing. Unix applications were easily ported to the new variant,
and people began using Linux for more than toy experiments.
As it became more useful, developers became more ambitious. "Wouldn't
it be nice if Linux did..." was a common question, and someone (often
the person who'd asked the question) went ahead and implemented the
needed feature.