In the US, the patent office almost always grants patents as long as the correct process is followed. They don't really concern themselves with whether a patent could be successfully challenged, they just care about whether the the application is shaped like a patent. They leave it to the courts to invalidate all the bad patents they approve. It's pretty terrible: the very least they could do is ask a random dude in the relevant industry whether there's anything novel there at all, and they don't even do that.