I just don't agree with it. Based on play alone, I find it hard to at least not include TM in the discussion. I understand the judgment is generally different due to the attention of the position, but the same excuses used for Suh and David (and many others - i.e. not having an offense, QB, supporting cast) could be and are used in comparing all positions, including QB.
Gill is widely regarded as the greatest ever on this board, yet no NC to speak of. Not winning in the post season vs winning in the post season (TM vs Gill / others) is more or less the same comparison as not winning a NC vs winning a NC (ala Gill vs Frazier).