Why is sometimes difficult to work with entrepreneurs

One of my best friends is a consultant and he came disappointed after a 6 months consulting program that he delivered for one of its clients. After 6 months he decided to quit because the solutions that he came with were not implemented. And I have to admit I been there before for a few times myself.

Why does this happen? Especially with entrepreneurs you put your efforts to deliver the best ideas you have, you are spending your time understanding their business, sometimes you do work pro bono and in the end they do not implement it. The same is true with managers in top positions hired by small companies or companies run by business owners. What is wrong with these guys? 

We praise entrepreneurs for their bold approach, for thinking ouside the box and for finding creative solutions to problems we all faced. But when it comes to work with them is a very difficult task. They have a real difficulty in accepting other people solutions and even when they say they want change they become the biggest change enemy.

I am sure there are many explanations to the subject by my personal oppinion is that they sometime develop a trust issue. Entrepreneurs success comes from their personal approch, therefore a strong personality and a “my way” approach to doing things and sometimes stubbornness. This comes most often with the price of considering other people way as being wrong. And when someone has a different approach you tend to disagree. It is difficult to work with entrepreneurs out of their box and in a paradoxical way is hard to change them.