It's a new drug and it's made by Pfizer and so the docs might have been detailed on it. Iclusig is not yet even approved in Europe, where some of the Bosulif support came from.
Most community oncologists might only see a few CML patients in a year. So no reason to be surprised that they may be fairly clueless about the latest developments.
Iclusig scripts are tracking well above the Bosulif trajectory in the US despite a later start, so some docs are clearly clued-in.