6'8" is properly tall, taller than me at 6'5". He is a skinny guy at 90kg, for his height, and you can see it pretty clearly. I have what I consider an average build at (now) 200 lbs/91kg, down from 210 recently. Regardless, it's great to see a truly tall ex-pro rider. All the cool fast bikes are designed for people 5'10" and under, and it shows (not complaining, just stating). Or maybe it's just Pinarellos. Make the tubes straight and the angles decent, and tall stuff works. Like vintage steel or many, even mostly-modern, Cannondales. Swoopy looks cool on smaller frames, just like curvy sheetmetal looks better on a Lotus Elise (rather than stretched over a '70s Sedan DeVille).
Big bikes are great.