I know that it is not necessary to allow reviewing the license at installation time and that it is not necessary to provide a translated license. But I choose to make the effort to have those possibilities (not so easy for the translation in the installer I must admit). While very few open source software provide a license translation, a lot show the license at installation time. In fact all the open source software with installer that I tried (and that did not start by saying that they are already installed) have shown the license in the installer.
And there is yet an additional usage of the license under text file format: the source package. It contains the license files that can be identified by its name. Its clearer than hidding the license text in the Aboutbox source file code.
If Linux installer does not allow to review the license at installation time that's not a problem. But I want to keep it in the Windows version.
It's true that in most of the files I created I did not add the copyright header because this is quite a small contribution and I did not feel the need to tag all my files. Though no information does not mean no copyright. It's just an unidentified copyright. By default you have no right to use anything except when explicitly granted. That's the role of the license (though it can be reasonably assumed that publishing a content implicitly gives the license to read it). But you are right, at the end nobody cares. In fact companies have to, when they use open source.
Philippe