To be fair, we got to the point where common usage of a word or phrase often becomes acceptable as correct usage about 50,000 years ago. That's how the English language came about in the first place. If we were strict linguistic prescriptivists from the beginning, we'd still be speaking flawless Ooga Booga.
I agree that some changes make the language less clear and might be ill-advised for that reason, and I also agree that some usages are not appropriate for all crowds, but let's not pretend the English language as it was taught in American schools in the late 20th century is the pinnacle of verbal communication.
Agreed. But lets also agree that given the ever-growing tidal forces of SMS and Twitter that we try to retain some legibility in our language and communications.
For example: Everyone one of you reading this has probably encountered someone using "U" instead of "you" in non-SMS business or technical correspondence. Is that laziness or extreme efficiency? Maybe they're still a Prince fan. Does it even matter to most people anymore?
I agree that some changes make the language less clear and might be ill-advised for that reason, and I also agree that some usages are not appropriate for all crowds, but let's not pretend the English language as it was taught in American schools in the late 20th century is the pinnacle of verbal communication.