10. They are faster. No pigments to cause aerodynamic drag.
9. They always look cleaner.
8. They can go with any color jersey, so they work well for OCPs.
7. They are lighter. Colors come from adding "pig"ments to white paint. Those "pig"ments add weight to the bike.
6. White bikes look good on any color car, if you are hauling them somewhere.
5. White bikes show off their decals better, if you have decals and want people to notice them.
4. Whit bikes look great with any color handlebar tape.
3. They are not as common, so not every Tom, Dick and Harry is riding one.
2. They still look good, even in black and white photographs.
And the #1 reason White Bikes are the Best is.......
1. MY BIKE IS WHITE!