Re: Diversity is good
General diversity is VERY advantageous. Think of the consequences of inbreeding. It doesn't just apply to genes, either. Incestuous hiring practices (think "the boss's kids") are also usually damaging. Or entertainment - do you really want them to make only Rocky sequels? Operating systems, programming languages, news sources, elected officials (look where our current monoculture has got us), food, medicines (think antibiotics as one example), clothes (do you really want to follow Chairman Mao's dress code?), religion or the lack of, courses of study, jobs, pets, vehicles, tools (think screwdrivers) ... diversity is essential for life as we know it to exist.
We've seen what happens when disease or pestilence attacks monocultures - they die. A good example is the banana. Today's banana is a sterile plant that cannot reproduce sexually, so the Cavendish bananas in the store all share pretty much all their genes, and are in danger of being wiped out by Panama disease, same as their predecessor Gros Michel bananas.
Similarly, any business that is not sufficiently diverse can get killed off by a change in the business , consumer, or regulatory environment - just look at Blackberry, Enron, Eastern Airlines, Radio Shack, Circuit City, A&P, Blockbuster (and VCRs and VHS and Beta tapes), Webvan, pets.com, Flooz, beanie babies, Yahoo! and Geocities, Chrysler (twice bankrupt), Worldcom, Peurto Rico (currently in bankruptcy protection), Trump University ...