Right, but you keep the knowledge you gained in making that stuff. Any useful product has to be rewritten many times before it's useful enough for people to pay for. So they keep the first draft - startups throw out their code and start fresh routinely, so again, you're not much worse off than someone who quits their job to found a startup.
> Any useful product has to be rewritten many times before it's useful enough for people to pay for.
On the other hand, people have been talking about launching early and often. Even your first version of something could well be good enough to launch and iterate upon.
All in all, I'd rather not give my employer any of my own stuff.
