I think you will find most of those degrees are going to be vocational degrees. I am not saying they are not hard work (law in particular entails a huge workload )and yes, you do have evidence to evaluate to some extent, particularly at the higher level. However some (vocational degrees in particular)are less intellectually challenging than others, in the sense of thinking creatively or/and with real intellectual rigour as opposed to 'learning facts.' With a degree in medicine or education I would argue you could maintain a JW worldview unchallenged. Apart from the above mentioned post pointing out the brainwashing aspect there is the cultural aspect of their being Americans. Having a strong faith is considered far more mainstream in the US than Europe. A fundamentalist Christian would be considered eccentric in a European university - less so in an American. I mean you even have Christian uni's in the states whereas education is strictly secular in much of Europe.
I will eat my hat the day you get a European with a masters or phd in philosophy become a JW.