Diversity is good not only for competition but also for security. For more information, I would recommend to read the article from Dan Geer about diversity and

Diversity is good not only for competition but also for security. For more information, I would recommend to read the article from Dan Geer about diversity and security - Monopoly Considered Harmful: http://users.ece.gatech.edu/~dblough/8813/geer.pdf http://users.ece.gatech.edu/~dblough/8813/geer.pdf