Having fought my way through a number of Greek and German philosophers, I can tell you that there is no shortage of dense and difficult material to read in the humanities. (There is plenty of English lit that isn't a cakewalk either). In my current line of work I often find myself reading technical papers involved in computer science and engineering. I can tell you that while there is sometimes math that I have trouble with and have to learn, the level of of writing is certainly not more difficult than Nietzsche, Wittgenstein or Joyce.

What I intended to convey was that in general the particular major probably doesn't make as much difference as we would think. I think it is misguided to believe that you can learn any career in four years at college, I would argue that it is more important that you learn how to learn, so that you can keep learning for the next 60 years of your life/career. A good student will use his or her time at college to develop meta-cognition.

As a matter of fact, a quick Google turns up a plethora of information about reading comprehension and meta-cognition (in both the sciences and liberal arts). There seems to be much less information about specific majors and meta-cognition.