It comes down to whether this thing you're making for fun is profit or for pleasure (of course it can be both in some cases for some people, see last paragraph)

It comes down to whether this thing you're making for fun is profit or for pleasure (of course it can be both in some cases for some people, see last paragraph). If you have a day job and need an escape, then don't bother with making it robust, polished and feature complete - just have fun doing it regardless of what the world may think of it, only thing that matters is what you think and what you get out of it. If you don't have a day job and your next project is going to be your source of income, then I think my original statement applies. What many do is turn the fun side project into a day job by focusing all their attention on it once they see potential in it and then start polishing, making it robust and feature complete.