Does a businessman have to be greedy in order to make his business successful?

No. A successful business depends on things like providing a product or service people will buy or use, and reliably supplying those products or services. It doesn't depend on greed. 

Just the opposite, the Business person who works on narrower margins and finds ways of cutting costs, usually are successful because they are being the opposite of greedy and giving their customers better value.

The most successful business is one that takes good care of their employees and their customers.

no .........................................

I would have given you an answer, but since you chose to exclude businesswomen in your question, you aren't getting one.

greed is a really bad word. Much business is win-win. Greed has nothing to do with it. When I had a business I made money by helping others. It was my work, not greed. I did not make a dime if I did not help others by providing them what they wanted.  If you work for pay are you "greedy"?