Well I would like to say yes they are getting old, but this seems to be for Americans the confert food of history. You know the bad guys, you know they are bad, because they are simply evil. Since we are not them, we are good. It is simple to the point and much like childhood. We had good guys and bad guys, it was clear cut. There is no need to develop characters and such since you know the bad guy is evil because he is Nazi and will kill or whatever simply because he is a Nazi.Bloodrayne as great as the game was, was fun and enjoyable because of this. Now right now they are starting to develop for something more. I don't think they will ever leave it because of the fact it is a world so simple, where Americans kicked so much ass. The world has changed since then, and hell America hasn't really been as great ever since. Kind of why it was repeated so often.
Now it aslo is one of a safe point to jump off of to do whatever. There will probably a game where you play as a terrorist, and I bet it will be against Nazis. It will be to some controversal, some it won't. The deal is killing Nazis is so the worry of wight if a person matters won't bother in. The Nazis are evil, they will continue to do evil unless killed. It being the only way to stop them. So it doesn't matter, they are just people to kill.
Now having that idea makes it safe to kill anything then. Killing Nazi babies with there own intestines is ok, since they are Nazis. If you don't kill them, they will kill you and maybe 10,000 more. They can be killed without worrying since you are stopping them from killing more, and spread that idea. That is a nice idea, since if you fill Nazi with something else, they seem to become some bit of a person. Then other questions are asked, with Nazis you don't have that.