As I pointed out in my post from last night, "three years out of high school" can apply to anyone from the age of 12 to 90.
Imagine that -- Wendy's founder Dave Thomas dropped out of high school and ended up getting a GED when he was in his 60s, so he would not have been eligible for the NFL draft (no matter how large, strong, and talented he was) until he was nearly 70 years old.
That sounds pretty arbitrary to me. In fact, I am willing to bet that if this case goes to court the NFL lawyers will not even bother trying to offer a rational explanation for their "three years out of high school" rule -- because they won't be able to do it with a straight face.