John,
Jeff B. will know more about this but the DMN says, "Panel members rated courses on a 1-10 scale. To be eligible for the top 100, a course needed to be rated by 25 percent of the panel members who participated. For this year's rankings, 87 panel members participated, so a course needed 22 votes to be eligible."
Now if the DMN panel members took into account (1. Routing 2.Quality of shaping 3. Overall land plan 4. Greens and surrounds 5. Variety and memorability of par 3s 6. Variety and memorability of par 4s 7. Variety and memorability of par 5s 8. Tree and landscape management 9. Conditioning 10. "Walk in the park" test ) then my non-scientific observation could be wrong. And it sounds like if your course didn't have at least 22 panel members show up you didn't get rated.