Because you defend it with religious fervor and tolerate no dissent. And apparently are more than happy to allow the courts to force in on an unwilling public.
It shouldn't be forced on anyone, unless they are taking a science course, and then they need to learn at least the basics of it. It should be taught in science class, not in a social studies course, a religious studies course, a theology course etc, now ID on the other hand, that should be taught in a religious studies course, or a theology course, but not in a science course.
Pretty simple if you ask me, teach science in science class, if it's not science, then it shouldn't be taught there.
Evolution is scientific, ID is not.
The only reason that it went to court was because the school boards were trying to force a nonscientific hypothesis, namely ID, onto an unwilling public, who believed, and rightly so, that it had not gone through the scientific rigors that evolution had, and until it has, it has no place in a science classroom.
The court agreed.
ID is trying to slip in via a public school curriculum, instead of through scientifically rigorous tests of it's hypothesis. This is not the way science is done.
Popular vote, schoolboard vote etc, does not a scientific theory make.