Is the proliferation of open source licenses just another example of programmers living NYI (Not Invented Here) syndrome?
IMHO, yes, absolutely. Take the Microsoft PL license as an example. It's completely redundant. Still, I like that one a lot because it's very clearly worded, much shorter than most other licenses and provides a good amount of freedom.
On the other hand, crafting a new license is fraught with risks because until it has proven its worth before an actual court it isn't worth the paper it is written on (if any).
IMHO, there are very few licenses that are worth knowing and using, among them GPL (which I personally don't like), LGPL, BSD and Ms-PL, and of course the Creative Commons licenses but these aren't suitable for software.
