It's not so much about "comfort" really as about being properly positioned for optimum handling. People talk about bikes' CG's and weight distribution all the time, but what they forget it that people have personal CG's and natural balance points too. Stand sideways next to a mirror and bend over. You'll see your butt move back without even thinking about it, since you're conditioned to automatically balance yourself. Try doing it with standing with your back against a wall and you'll feel off-balance and awkward, and will feel your core muscles being worked hard to compensate. Sound familiar? that's what happens when you introduce fixed contact points that don't allow you to stay balanced. So the real point is being balanced on the bike and spreading your weight evenly between hands, butt and feet. I've spent 5-6hr, 200K+ days on a road bicycle with far more reach and drop to the bars than any sportbike, and felt balanced and "comfortable" the whole time. And I guarantee you'll feel better in the corners on a bike that's dialed in to your personal anatomy than an off-the floor model.
Agreed. And if you talk to someone who races endurance comfort comes into play. A comfortable rider is a relaxed rider and therefore a fast rider. The performance levels of these machines no longer dictates the need to be uncomfortable. Look at the CBR and GSXR as good examples of this. Look at the MV as the worst. Meanwhile the performance advantage in this case goes to the Japanese.