Nitro the Guru said:
Do you believe that people who are subject to these cultural elements have the right to "complain" about not having anything, even when they talk this way knowing full well it will be rejected in most professional work environments?
Partially, I believe you are right, yet there is a split in our beliefs that should be enunciated. People who are raised in a complete environment of ebonics/slang/etc often have never heard professional speech, or even heard enough to go on in terms of an example to work from. Case point: often in interactions with black people, (both adults and kids) who get asked a question, talked to, etc. by me, in mid-conversation, their phrasing/tone of voice instantly changes to address me.
"Nigga hell nah" to a friend becomes "I'm not sure" as they attempt to bridge the perceived gap between black and white speech. I see the same phenomenon when white people address black people and attempt to put some amount of "slang" in their voice. Once a nerdy ass old white guy loaned a black kid who was short some money for the bus. After the kid thanked the men, he replied "Dont trip"...and in a way it was obvious he wasn't that comfortable with the phrase. My pops, who speaks Spanish, goes into his little "Spanglish" accent often when talking to Hispanics.
You see this in white kids trying to be down who truly did not come from ghetto situations...their use of slang and vocal approach is *kinda* like black people talk, but it still misses the mark. They seem kinda hood, but you can tell they stop short. In the same way, a black kid from abject poverty, who is and was never exposed to proper speech, is going to fall short of the mark in trying to sound professional, and instead of being possibly laughed at, (as the old white man was) will simply not attempt it.
There was an interesting study of young black children in detroit with difficulty in school. Poor children (especially black children, who are disproportionately poor) get read to less by their parents growing up. They are also often disciplined less, as single-parent black households are extremely common. They learn to act in their boundaries just far enough before they get in trouble. Often, black parents use the TV as a babysitter (A fact obviously true not just in black families).
We've all heard of the concept of poor children having to raise themselves or having to grow up fast. This is in part due to adrenaline and other "survival" hormones produced by children dealing with stressful or dangerous situations. A side effect of this chemical production is the faster "maturing" of the brain...leading to a stunted ability for the brain to develop in areas dealing with knowledge and intellect. Basically, if a kid has to worry about survival, food, an abusive parent, etc., the brain "grows up fast" to cope...and what gets sacrificed is the necessary slow growth of the section of the brain dealing with intellect and a child's ability to learn without distractions.
Children entering school having never been read to have a harder time associating letters and words with concepts (which, believe it or not, is a skill). Children who watch mass amounts of TV tend to have more attention and behavioral problems stemming from the fact that it's harder to keep them interested. In addition, children with behavioral problems tend to gravitate towards other children with the same type of problems. Furthermore, black kids tend to find cultural commonalities in other black kids to bond with.
Put this together, and you have a cocktail for a group of kids fundamentally behind the rest of the class. Fast forward to high school, and it becomes a group that is not interested in proper speech, mathematics, or any other school consideration. These kids have been discouraged while attempting to learn, feel "stupid", "inadequate", etc., and take the safe route, hanging out with other poor kids, or other black kids, who speak and act the same way they do.
You make it sound like it's a choice of black people and others who grew up poor to speak poorly and come off unprofessionally. I'd say it's the opposite. They don't know any other way, and the easy way (and what seems the most logical choice) is to stay within the boundaries of what they know.