Because open source has a very specific definition which the licensing on this application does not conform to. The ability to produce derived works is a key attribute of open source.
And I understand that these are your thoughts, but what I'm looking for is a clear and legally enforceable license, which seems to still be missing.
And I understand that these are your thoughts, but what I'm looking for is a clear and legally enforceable license, which seems to still be missing.