I own a small business in which all my employees (artists) currently have at least one University Degree. That being said, if a candidate without a high school diploma can make my business money (and is pleasant to work with) then I would hire them with little hesitation. Past results and work history are the deciding factors. A PhD is useless to me if it doesn't bring results along with it. Make money for my bank account and you can be a Kindergarten dropout for all I care.
Some people drop out because they are lazy, stupid, a criminal, did drugs, or got pregnant (if a girl).
But so many people don't realize that not every high school dropout is the same, and that is why high school dropouts have a negative stereotype.
Don't believe me? Look up "successful high school dropouts."
But I believe it depends on the REASON why he/she dropped out (not the fact that he/she dropped out at all) and if he/she still determined to get an education.