Mark Cuban hasn’t been afraid to share his thoughts on business and investing, even if he has ruffled some feathers along the way. Some of his investment takes are pretty basic and politically correct. Avoid debt, learn constantly, be patient and only invest in what you understand. That’s pretty straightforward, but Cuban hasn’t always given investing tips that everyone agrees with. The billionaire entrepreneur stirred up controversy in a 2011 Wall Street Journal interview by saying that “diversification ...