I see examples of this all over the place. I have even fallen victim to it myself. In fact I find that the more time I spend around the people of my particular region, the more I begin to lose touch with my grasp of proper English. Now the purity of one's English could almost be put on a scale:
Pure to Pure Sh...err Something Else Scale
1)The King's English...it's correct but who the hell could listen to you talk that way all day.
2)Oxford English...if it was good enough for Tolkien, though you come off as sounding like a professor.
3)Canadian English...this being the one I am most familar with it feels the most natural and neutral. A blend of both the proper and the contemporary.
4)American English...similar to its Canadian counterpart though it has the history of being isolated from the European English for longer, thus producing many colorful and often useless phrases.
5)American't speak good....this is the slower, hit too many times on the head little brother of number 4. Only existing for the past century or so, this is the result of lowered education, lowering respect and increased use of slang, shorthand, acronyms and other devices to "aid" in communication. (*note: American't Speak Good is not limited to the United States.)
6)I should probably avoid naming this one, as it might completely offend someone. This one really can be defined by its state of being lower than number 5. It can come out of a lack of education, backwoods dialects, laziness or many other factors. Its prime example is the use of internet memes or cultural lexicon either out of context or in everyday vernacular when unnecessary.
The further down this scale the more information is lost. Rather than attempting to package information in tidy easy to decipher bundles, we continue to befuddle them. Things get a little lost in the translation (assuming there was something of value there to be lost).
Many of us can be the culprit, and most of us have. Some do so unintentionally, others may not even know better. To me, it is those that do not try that are the hardest to swallow. Do not hide behind culture and claim that the way you speak is 'part of who you is' (sic). Inability to communicate is hardly a cultural trait I would want to cherish. Especially if it can come with the stigma or stereotype that your entire group is therefore uneducated.
Now to not seem like I am being too harsh on one particular group, here are a few links to the wonders of the English language, here and abroad.
BBC needs a headline checker
Leprechaun in Alabama
Top 20 Songs with the worse grammer
What if rap used proper english?
The future of advertising.
Bad Grammar Makes Me Sic graphics and merchandise are available at OneHorseShy.