Sometimes we have these moments when something just clicks, and you understand why you believe in something. One of the biggest criticisms levels at Linux Distros, is that were they to combine, they could share their resources and develop faster.
Whilst I'd hazard a guess at this being true with tribes, and 'ye olde style' warfare - in the software world it is exactly this diversity which adds value. Many groups of people can be coming at the same problem from multiple angles - many of which the other groups have yet to consider as viable/worthwhile. Therefore you get a variety of methods.
Working on the commercial side of FLOSS, there are a number of Open Source 'products' that we re-sell and support. We add value as a local supplier, and help with end-user support and other IT problems. The real value we add though, is that we look to support anything (and yes, that includes Vista). When developing websites, we use a number of FLOSS CMS systems, with each system being a better fit than another for a particular use. Sure, standardisation may be good on paper... but constantly learning new systems and seeing different approaches adds value to your staff. Keeping them actively learning stops stagnation, and can only be good for the company in the long run.