Disrobing of Draupadi in the Mahabharata

Question: In the Mahabharata, when Draupadi was being disrobed by Dushasana, why did the Pandavas sit quiet? Is there any other reason besides the fact that they had already lost in the gambling match and had become slaves? The primary duty of a husband is to protect his wife. How could Yudhisthira Maharaj fail to understand this?

Regarding Draupadi’s disrobing, here are the main points as I see it:

1. The Bhagavatam many times gives the highlights of Mahabharata: a) in Bhishma’s prayers; 2) in Kunti’s prayers; c) in Arjuna’s and Yudhisthira’s recollections after Krishna leaves this world; d) in the description of Vidura’s pilgrimage after quitting Hastinapura; e) throughout the 10th canto; f) elsewhere.
The Bhagavatam mentions the insult to Draupadi four times in these verses: SBh 1.8.5, SBh 1.15.10, SBh 3.1.7, SBh 11.1.2.  Remarkably in all four cases, the Bhagavatam states that the insult to Draupadi was touching/pulling her hair. There is not a word about disrobing, nor about Yudhisthira gambling her.
in Vedic culture, human beings are not commodities to be bought and sold. Lord Krishna directly states this in Mahabharata when Balarama and other Yadus furiously protest that Arjuna took Subhadra without giving gifts to the Yadus. In fact, if we study feudal law, I believe we get a clue to the gambling match which took place in a type of Vedic feudal society.
From Wikipedia: “…feudalism describes a set of reciprocal legal and military obligations among the warrior nobility, revolving around the three key concepts of lords, vassals, and fiefs.”
I that Yudhisthira gambled away his brothers in the sense that he gambled their legal and military obligation to him as their older brother and King. Just as today a financial obligation is a negotiable instrument that can be gambled, auctioned, sold, bought etc, so in ancient societies, military and political obligations were similarly negotiable instruments. I believe that Yudhisthira thus gambled away the obligation, not the people, though it would be normal to say, as Mahabharata does, that he gambled his brothers.
The relationship between husband and wife in Vedic culture is not political or military and cannot be negotiated or gambled in the same way. Interestingly, neither the Bhagavatam, nor the CC mentions the attempt to disrobe Draupadi.
2. If for the sake of discussion we assume that the Kurus did attempt to disrobe Draupadi, then why did Yudhisthira remain silent? In the description of this incident found in the Mahabharata (which Madhvacarya declared to be a highly corrupt text), Yudhisthira falls into the same ethical misunderstanding that Bhishma fell into many years before: act-based ethics. This ethics theory states that moral good lies in the act itself, regardless of the act’s consequences. Thus if you are sworn to tell the truth, then you should tell the truth, even if by doing so you cause terrible suffering to innocent people. Example: a person, with nor risk to themself if they life, “honestly” reveals to Nazi soldiers where Jews are hiding. Consequences don’t matter, only the act.
In Mahabharata, Krishna tells Arjuna a similar story where a sage revealed the hiding place of innocent citizens fleeing from murderous thieves. The sage kept his vow to tell the truth, revealed the hiding place, and caused the death of the innocent citizens. Krishna then states that because the sage told the truth, he went to a terrible hell. The sage should have lied. Krishna tells this story to Arjuna, because when Satyavati begged Bhishma to save the world and beget heirs in Vicitravirya’s widows, Bhishma replied that, basically, even if the universe blew up, he would keep his vow. Consequences don’t matter. But Krishna makes clear that consequences do matter. A complete description of an act includes its consequences.
In the Mahabharata version of the gambling match, Yudhisthira feels he must honor the result of his gambling, and that this “honesty” trumps all other moral duties, such as protecting a chaste, pure Vaishnavi wife who is virtually a goddess. Yudhisthira ignores consequences, in this version, and thereby acts badly. Even Draupadi often berates him during their forest exile. To make matters worse, Yudhisthira fails in the one chance he has later to redeem himself. Draupadi begs for protection from the lecherous Kicaka during the Pandavas’ incognito stay in Virat. Yudhisthira insults Draupadi and again refuses to protect her. I don’t believe this Mahabharata version reflects the real character of Dharma-raja, whom Krishna personally restored to the throne. In the Bhagavatam, Yudhisthira certainly faces challenges and struggles, but the Bhagavatam does not confirm Yudhisthira’s worst behavior as found in the Mahabharata.