Student grammar failure?

A recent report from The Canadian Press cites social networking sites, texting, and the lack of high school education for the increasing number of post-secondary students who are unable to write correctly. For years this has been a complaint of professor's and one university believes it now has proof. Ontario's Waterloo University is one of the few post-secondary institutions in Canada to require the students they accept to pass an exam testing their English language skills.
Shocking to the faculty, almost a third of those students are failing which is a jump of 5% in just a few years. Such writing horrors as emoticons, happy faces, sad faces, cuz, are being handed in, say professors and administrators.
So, is this linked to Facebook, Twitter, and constant teen texting? Or could it be linked in greater degree to a lack of competent education on the high school level?
I'm not sure of the answer, and certainly do not have the studies to back it up, but I do know from experience that we generally learn from repetition. If the greatest repetition high school students are exposed to is using texts, emoticons, and snappy abbreviations, then how will they successfully learn to write complete sentences using the correct tense?
As for a solution it seems that these post-secondary institutions need to get this message out to high schools so they can raise the bar on English competency. Or perhaps a text message to the potential students would work; something like, "omg, ur writing sux! better get 2 school n study more if u evr want a job...lol!"