As a first responder for the last 15 years, in a prime motorcycle riding area, I unfortunately have LOTS of experience with single-vehicle motorcycle crashes.
In my experience, SR's and target fixation are at the top of the list for causation, as the VAST majority of riders who crash entered the turn traveling a speed at which the motorcycle was capable of negotiating the curve. Most riders who crash (single vehicle on the street)attempt to reduce speed or stop, and depart the roadway to the outside of the turn before they go down. A significant number of cruiser riders who go down on the road lock the rear brake before falling. Rear brake stomping is less common with sportbike riders, but front brake crashes are relatively uncommon. It's much more likely that they will target fixate, and run off the road while braking and then fall down when they leave the pavement. Interestingly, crashes due to road condition (gravel, sand, etc.) are not really that common.
So what can we learn from this: As Keith notes, getting on the track and getting some coaching pays huge dividends in safety on the road. In my experience most riders crash because they enter a turn at a speed they perceive to be too fast, and SR's, target fixation, and a lack of skill cause them to panic. Track time will teach you that most modern sportbikes are capable of entering a turn at a speed that would cause heart failure for most riders; but knowing this can keep you from panicking.
The above is anecdotal, but based on 15 years of picking up the pieces (and sometimes the bodies), 5 years of serious track riding/racing and 3 Superbike schools (plus a couple of Keith's competitors'schools that I won't mention!).
Push it on the track, not the street!