Another person with a BA in Language Arts (various aspects of English, including Linguistics, Drama, Journalism as well as the traditional Literature and Writing). I loved my Linguistics course, and only wish there were more offered at the small college I went to (and that it hadn't been a Senior level course, where I really wasn't given the option to study it more in depth).
While I agree that language constantly and necessarily evolves, there is a degeneration in formal English that is appalling. Because of my background and degree, I am the default person that the Engineers that I work with go to for proofreading. Some of the sentences (and I use that term loosely) they come up with are barely understandable! These are letters going to public building officials for building code clarifications, or responding to code reviews. These guys are very knowledgable in their field, have college degrees, and still can barely write in English.
Now add to this the new "netspeak" which is barely understandable to begin with - missing entire words, turning real words into letters, and being too lazy to type out a 3 or 4 letter word instead of a 1 or 2 letter word. There is no differentiation between to, two, and too or their, there, they're, let alone through and threw and thru (the last one is used in my industry almost as standards, as in RTU-1 thru 10), and know and no.
I realize that there is a time and place where netspeak is acceptable, just as eubonics also has a time and place. However, what seems to be slipping through (not threw or thru) the cracks is that the written language is what gives people the first impression of you in the business world. If you cannot string a complete sentence together, you won't be taken seriously no matter what your credentials in your chosen field. If you can't state your career objective in a complete and understandable sentence or two, with proper spelling and grammar, on your resume, you will be shortlisted in the round paper file in short order.