Sumner and Fil, the debate is moot. To divine the rationale for the punishment on the basis of the bylaws is a quixotic quest. There is no definitive answer. Sumner probably comes closest by placing the punishment in the context of the collective and individual NCAA membership's willingness to stay in the fold.
The NCAA has wielded largely unchallenged power for decades. Although there are notable exceptions, the members, by and large, have not sought to challenge individual rulings or collective general activity by the NCAA because they haven't seen it as being worth it or in their best interests. Besides, most recognized that the very nature of membership - generally - has no legal foundation (several court cases notwithstanding) upon which to base a challenge.
In this sense, NCAA "challenges" are not legally based, but come closer to being mere pleas for mercy.
And Fil, you have it right as well when you point out that "the respondants were so weak-willed that they signed it. Too bad for them." That dialogue has probably played out in the backrooms much more often than the general public knows.
