It's the whole descriptive vs. prescriptive thing, and MW explicitly adopts a descriptive standard (they say so in their preface). A good introduction to this larger question is David Foster Wallace's (excellent) essay in review of Bryan Garner's (fantastic) usage guide (http://harpers.org/wp-content/uploads/HarpersMagazine-2001-0...).
If you are interested in usage, and are not familiar with Garner's book, I recommend it. (http://www.amazon.com/Garners-Modern-American-Usage-Garner/d...) It is superior to MW for most writers' purposes. (For students of linguistics, MW might win out.)
Garner, incidentally, doesn't much like "comprised of" -- http://www.lawprose.org/blog/?p=2385 (“invariably inferior”).
I recalled David Foster Wallace's effusive praise  for Garner's Dictionary of Modern American Usage  which seems to have similar characteristics to the Webster, but I doubt there's such a convenient digital integration available for this.
If only the world were perfect! ;)
An illusion; a conjuring trick; a deception, an imposture.
>As professors focus on their research, and students worry about securing career opportunities, both sides become increasingly disinterested in the classroom.
This sentence is atrocious, not only because of the use of "disinterested" for "uninterested" (Bryan Garner classifies this usage as Stage 4 on the language change index, meaning that it is ubiquitous but still not quite accepted ), but because the meaning is ambiguous. Are the views of the students about the idea of classroom learning changing, or do the students feel apathetic inside the classrooms of professors who ignore cheating?
Another poorly written sentence:
>The roughly 30-member committee was established in the fall of 2010 and includes about eight student members.
This sentence would be fine in informal speech. In formal writing, especially in a respected newspaper such as the Crimson, it is unacceptable.
Somewhere, John Simon is muttering under his breath.
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