Accuracy vs Precision
I think we could all benefit from a little logic refresher: specifically, the difference between accuracy and precision. Simply put, accuracy is whether you hit the mark, while precision is how well-defined (or small) the mark you hit is. For example, "Pi is just above 3" is an accurate statement, but it's not as precise as "Pi is approximately 3.14159".
Here's another example:
A contract is a legal agreement between two or more parties. (I know there's more to it than that, but I'm going for accuracy not precision here.)
A license agreement is a _contract_ with respect to a work protected by patent, copyright, trademark, or other laws. (There's your precision for you!)
So Mr. Goodin was right when he called the GPL a contract, he just wasn't being very precise. But "Idiot*" was wrong when he said a license was backed by copyright law and not contract law. A license is backed by copyright law AND contract law. Licenses (GPL included) often include terms such as limitations of liabilities and of warranties for specific purposes which are not covered by copyright law.
"Free or Libre" and Matt Kern both raised some good points, although I disagree with their interpretation of the article and its purpose. I don't think the article was really about the money (although that was the hook), and I don't believe the Mr. Goodin should be required to recap the entire history and current state of GPLv3 (interested parties who don't already know can google -- oops -- "search the web for" that.)
What I see as the point of this article is that the actions of the SFLC seem to imply that GPLv3 is much more complicated than v2, and that this could be a problem for a document which has historically been perceived as an attempt to simplify licensing.
Personally, I see this as a reflection of the larger legal environment: it's legally and politically more expedient to create special exceptions and complicate law rather than to retool existing law to make it simpler and more logically consistent. Consequently contracts such as GPLv3 have to be more complicated as well.
*I don't necessarily think he's an idiot, and I'm just using "he" as a neuter pronoun, because he didn't bother leaving a name.