Some go from a 1300cc cruiser to a GSXR1000 or Hayabusa and have no clue that the world can blur like in the movie fast and furious... They then sell cause it scares the chit out of them and I can't blame them, LoL... I've ridden all my life and I still laugh my azz off when I open up my K6 GSXR1000, what a great rush...
As for comfort, could be, it takes some time to get use to a sportbike riding position and riding through traffic with constant stops etc... They may not give the bike a chance... When I first bought my K6 Katana750 I thought ohhhh chit its like riding on the back of a buffalo... It took quite a bit of time to find that I actually enjoyed the stance, As for my K6 1000 same thing but it only takes about 15 minutes before I start humpin the bike, LoL...Its a lust thang...