I stand corrected. Perhaps my point (or my understanding) then is more subtle. Perhaps what I mean to say is that the GPL license comes with additional virility

I stand corrected. Perhaps my point (or my understanding) then is more subtle. Perhaps what I mean to say is that the GPL license comes with additional virility, not found in BSD et al. Perhaps the difference is most noticeable in libraries (where I do most of my work). Using a GPL library in a commercial app is generally impossible, where BSD (or LGPL) etc is completely acceptable. In my experience companies are allergic to GPL specifically, whereas other licenses - especially MIT and BSD are far more palatable, and are frequently used.