People were unhappy with the terms of the patent grant: it stated that FB would grant you a license to its related patents, BUT, if you were to sue FB for patent infringement, your license to use the covered software is terminated.

But I very much agree and am puzzled why everyone seems to think this latest move is such a great thing. Removing the patent grant entirely isn't so great.

It's a response to placate folks who pick a stance based on the memes that the newstides wash up. In other words, it's not exactly good news at all, it's just a really big deal.