There is a list for licensing issues involving perl6. I do not want to go into details, but the current Artistic License is not exactly the best license in the world to use. If you just want the world to use it, you could make it public domain. If you want to be remembered then I would suggest BSD or MIT style licenses. As you note the GPL has a specific philosophical goal. If that matches your goal, well and good, but it apparently does not.

As for why the Artistic License has multiple versions, well it would appear that the license has been patched over time.