Yehudah: villain or hero -- take 2

Last week we discussed the machlokes between R' Meir, who is highly critical of Yehudah for telling the brothers that it was not in their best financial interest to kill Yosef, "mah betza ki na'arog es achinu," but rather to sell him, and other Tanaim who disagree and do not share his criticism.  On the other hand, one could argue that given the danger Yosef was in, Yehudah did a great thing by simply ensuring that the brothers did not actually kill Yosef.  On the other hand, R' Meir looked at the potential Yehudah had to do so much more.  Had Yehudah exerted himself more forcefully he could have returned Yosef home. 

There is another possible hesber of the machlokes.  Chazal tell us that a when a person sins, he is overcome with a "ruach shtus."  When a person has a taavah, what it says in shas and poskim goes right out of his mind -- all that matters is satisfying the "I," the ego, the subjective need/desire.  Had Yehudah argued with his brothers not to kill Yosef because it says "lo tirtzach," he would have gotten nowhere -- the yetzer ha'ra was in control already.  However, he could still make the argument that the "I" would get a better deal selling Yosef rather than killing him.  

Is this approach a b'dieved, or can it even be a lichatchila?  If a person, for example, doesn't eat at McDonalds because he tells himself that he is better off without the cholesterol and fat, that the net gain of skipping the Big Mac outweighs the enjoyment he might get from having it, is that on par with a person who doesn't eat the Big Mac because of a pasuk in chumash?  R' Meir is critical of Yehudah's approach -- we should aim for more than convincing ourselves based on arguments from seichel with it comes to avodas Hashem.  Other Tanaim take the opposite approach, that this is not something bad at all.  (Based on Mei haShiloach)