That depends entirely on the goals of the original author (Matt and the Wordpress team, in this case). Judging from Matt's reaction, I suspect the LGPL would have produced the opposite result they were looking for.
You miss the point. The LGPL was created to allow people to do what Chris wants to do. The GPL was created to prevent people from doing the same. If Chris is actually right, the GPL and LGPL are equivalent. In that case, damn! I should have used GSL instead of rolling my own numerical methods for a closed source project. And I should sell a GUI frontend that links against GNU Octave.