1) Because getting rich is pretty hard.
2) Because we haven't been trying all that hard.
Most people who get rich probably got there in one of three ways:
1) Be born with rich parents (or other relatives)
2) Marry someone who's already rich
3) Enter a career path in which it is possible to make lots of money, then be successful enough in that career path to become rich.
My brother did #3 - he won the Goldman Sachs internship lottery, got hired into a permanent position, then, a few years later, jumped ship to a hedge fund that offered him more money than his boss was making. (He even took every one of his co-workers at his trading desk with him, much to the dismay of both his boss and his boss's boss.)
I've not made the attempt. My brother worked his ass off in a way I don't want to duplicate, and it's perfectly rational to decide that there are more important things in life than the expected size of one's paycheck. ;)
This thread is for asking any questions that might seem obvious, tangential, silly or what-have-you. Don't be shy, everyone has holes in their knowledge, though the fewer and the smaller we can make them, the better.
Please be respectful of other people's admitting ignorance and don't mock them for it, as they're doing a noble thing.
To any future monthly posters of SQ threads, please remember to add the "stupid_questions" tag.