Multiple, actually. No one can keep up with him for long, so they swap out. Each concierge (usually called "Domestiques") sweeps the path clean of all gravel, dirt, and random people with strollers for the rider.
(I just realized how much I miss /r/bicyclingcirclejerk.)
It's more that you are seeing the f1 equivalent in bikes. They are redesigning these chasis, wheels, etc every year for competitive advantage. Add in all the customizations, being hand made, and using very expensive materials and you get very high prices. It's easier to see the jump in cost because we can actually see those differences in price more readily from the $100 Wal-Mart bike to the 15k bike. How many times do you compare a basic econobox car to an F1 car? That would be insane, one is about utility the other is about pushing performance at all costs for competitive advantage.
I met a guy at a party who said he was into cycling. I told him I used to like cycling but my bike is so broken the repair tech said I should cut my losses and get a new one. He started giving me advice about what wheels and tires to put on my new bike. I asked him how much they would cost and he said they weren't expensive - just about $1200 per wheel. Turns out this guy was significantly richer than me.
Carbon fiber wheels, carbon fiber frame, high end bearings, location of manufacture, billet machined parts from titanium or aluminum, and the brand tax.
I don't get it but if you got the money for the nicest and lightest ride; why not?