I have most of my family in the south... know lots of blacks from the south... not one of them says AX in place of ASK.
It's a combination of slang and ignorance. The fact that kids are growing up anywhere and ONLY speak Ebonics is very sad. The fact that if you do a spell check on ebonics Outlook will add a capital E, is even worse.
Only in America is it cool to sound ignorant.