Bright colored hair tends to add more light to the rest of the package especially in natural sunlight
Men are visual creatures after all.
Brunettes and Black Haired ladies are also 100% totally awesome. Their elegance is a little more subtle and the market for this is huge especially after age 25.
Men in general love cars so an example: Blonde would be a shiny red car and Brunette would be the same in grey/silver. Under the sun, both look absolutely spectacular though different and both have their stable markets.
Lastly, since I went to a white dominated high school, its occurred to me that blondes made up like only 5% of the total white population.
So i guess they're special and sort of like yellow bones for us brown skinned peeps.