Troll Tech's stated goal is to be compatible with all of these licenses which meet the Open Source Definition (and because of the origins of that document, the Debian Free Software Guidelines).
If that is the goal, they definitely need to change the license. The present QPL does not meet that goal. Using the GPL would cause that to be not easily possible. I propose that they include the GPL as an alternative, either in the same way Perl offers the choice of the GPL or the Artistic License, or in the same way that the LGPL says you can use the GPL instead. That would be compatible with the GPL, and also compatible with other free software licenses if the present QPL is.