Do certain cultures preventing economic progress?

If there was one thing I took away from business school, is that incentive matters, a lot.  You cannot be rewarding behavior A while hoping for behavior B to happen.  As such, I have observed a potential flaw in the African culture that could potentially prevent one from doing hardwork and making economic progress on the micro-level.

One key cultural theme I kept coming across is this bittersweet burden of success for Africans.  I've met a few successful Africans now who have,  in one way or another, pull themselves out of the poor villages they came from.  Quite a few was even able to get scholarships and study abroad.  Now, they've completed a good education, and got a good job...but the quandary is, the more successful they become, the more responsibility they begin to have, and the more people they need to carry on their shoulder and take care of!  When you were just a student, maybe you just need to care for your immediate family, but the minute you've "made it" in the world, more people come knocking at your door, wanting assistance, and it's expected that you take them in.  Saying no seems to not be an option.

I see this happening everywhere...For example, someone just come up to you asking for money, I will have no problem turning them away, but there's a good chance my African friend will give something (20 kenyan schilling, a candy pop...etc.)...A group of friends going out, the one with a part-time job will end up paying for the one without a job (while I would normally argue that the jobless person has no business out partying to begin with)...this no questions asked form of "help" really intrigues me.

Sure, for those much is given, much is expected; I mean, this is not such a novel concept, Muslims would take more wives if they were more financially able thus can take care of more people. However, to me, there could potentially be a serious free rider problem.  Why does the fact that I have money justify your taking a piece of it?  I worked my butt off to earn the money, what have YOU done to take it from me besides the mere fact that we are somehow related or acquainted?  This seems tremendously unfair and demotivating for someone who's worked so hard to achieve success!  Is it so "selfish" to want to enjoy the fruit of one's hard work?  I'm not sure where I would draw the fine line between "being selfless" and "being taken advantage of".  

Do you  give because you are given more talent to earn more thus have the obligation to support others?  Or do you keep what you have because it’s your hard earned money and those who just sit around should get off their butt and work for it themselves rather than expecting a hand out?

I have tremendous admiration for the strong sense of community in Africa, but sometimes I wonder, if this culture is prohibitive of economic growth because it is, in a way, a system that punishes hard work and success.  Imagine, if you've made it abroad, what is it that will encourage you to go back to your home country when you will be first and foremost greeted by a bunch of empty hands, requesting support in one shape or another.  and if you've made it within the country, what's going to keep you going when every phone call you get is about a problem you'll need to solve?

Maybe I'm not selfless enough to think this way, and maybe this is why I get offended when people expect me to pay for things because I'm a mzungu and supposedly more wealthy...