Good for them. As much crap as I give Bethesda for buggy products, they actually evaluated how things needed to progress from the standpoint of someone who wants to play a game and released something which improved on their earlier work. I hope all the excuse makers at Bioware who decided that Dragon Age 2 failed because there was no market for this type of game take a few moments to let these figures sink in.
This product is a success because the core product has appeal that can be spread by enthusiasm carried over from prior products, word of mouth, and the ability to endure under critical scrutiny. It leaves the retarded fringe crap up to the modders to create, rather than letting the writers and developers indulge in it.