Claims like these are about 90% bullshit and 10% rooster diarrhea.
On the one hand, you've got the claim that allowing kids to use "slang" (official vocabulary is just slang that's been around by the way) somehow decreases or impedes their literary ability. I know it feels true to you but I'd like to see some properly designed study say it. I can't imagine how using language more flexibly could possibly harm literary rates but I'll listen--again--to any properly conducted study you'd care to show.
On the other, you're seeing the same old drivel about "our country" (it's a UK article, but they do this shit in the US too) not producing qualified workers. I can't attest to how it is in the UK but in the US, that's just horsecrap. We have plenty of qualified workers, they're just hard pressed to accept less-than-living-wages for jobs that are posted with heavy degree requirements*. The companies here use it as an excuse to show that they need to outsource. "Americans aren't qualified!"
And if our workers really aren't qualified, why is that? It's because our education system is a failure. Who's responsible for that? Maggie Thatcher, Ronald Reagan, and all those who put them into power and let them do what they wanted with impunity.
*Sometimes impossible requirements. I remember when Ruby was about five years old and there were job postings for it demanding 8 years experience in it. The pay for that job? $12/hr.
ETA: Since I accidentally left the first paragraph in and feel sheepish taking it out, I'll clarify that the third paragraph covers the rooster diarrhea.