I agree.

There are lot's of good reasons to open up the code.

Like, there will be lot's of people helping you find the bugs and debbugging them. Or lot's of people porting your program to different systems, and such.

I know that it's weird to think of letting everyone see your code but, hey, don't authors let readers see their books? And don't singers let people read the lyrics of their songs?

You've done a great job, why not complete it by opening up your code?