I agree that there is generally nothing wrong with flying the aircraft by raw data to maintain one's edge. However, I have seen pilots who fly raw data departures and arrivals in very busy airspace without so much as a quick look out of the window. One of these pilots explained to me that "scanning is what the right seater is in here for!"
I am all for raw date proficiency but not to the exclusion of a safe traffic scan,when in a high workload environment.
Lets not forget that two sets of eyes are better than one.
Regards,
Trinflight