I don't remember if this is opt-in or not, but I do not have it in my Firefox. Maybe I just removed it myself immediately after first install, when I went through to update all of the privacy and other browser settings.
I agree that it seems like a crappy extension, and people should be upset about things being preloaded to their browser.
But there's a point here to be made, that if you're concerned about privacy at all today, you need to look at the settings of any software after you install it. It doesn't matter how much previous trust you have for the developers. This should just be default behavior so that any surprise is met immediately, and not after any damage it could perform has been done.