It's not easy especially in an economy where things are very hard. Let's take a man with a wife and children to feed and send to school, he might not have that patience to work on his passionate because there are bills to be paid.
That is why some have no other choice but to continue the job that puts food on the table while they gradually work towards their passion.
Yes I totally get your point, the country a person finds themselves can either make it easy or hard to follow their passion, and countries like Nigeria can frustrate one's dream. This is why it's usually better for a person to start working on their passion when they are still under their parents roof, it's much easier than doing it when they have started their own family and saddled with the responsibility of providing for them