Comment by Ekaros

I think it comes to analogies, with open source you have a public park you are free to use. With source available it is public park you are free to look at behind a fence... So not actually public park. Still a fine thing to exist.

As user as well. Difference between I can use this for free and I have to pay to use this. Even if I can see parts inside is significant.

It might not be real principle, but at least it is real difference.