All the reasons given so far are fairly accurate and I have noticed that as the super popular bike that LA rides, I often see people out riding on 5k bikes that ride once a week at best and just bought it because it "is the best bike because LA rides one".
The only problems I have with them is that they do overprice some of their models and carbon made in the USA isn't necessarily the "best" carbon(just cause it is made in America doesn't make it amazing), Taiwan is typically the leader in CF.