Mike,
I have heard multiple scouts, coaches and GMs complain about how the spread offense (what you refer to as the modern offense) has made it much more difficult to scout NFL QBs (and once drafted develop them). The spread offense is so different from what is done at the NFL level, as compared to the more traditional college level pro style offense) that the QBs coming out lack experience as something as basic as taking the snap under center or calling a play in the huddle or at the line of scrimmage. Most of the spread QBs haven't even worked a full route tree. When it comes to spread offense QBs the best NFL scouts can do is scout athletic ability. That makes the difficult job of scouting college QBs much more difficult.
I have heard multiple scouts, coaches and GMs complain about how the spread offense (what you refer to as the modern offense) has made it much more difficult to scout NFL QBs (and once drafted develop them). The spread offense is so different from what is done at the NFL level, as compared to the more traditional college level pro style offense) that the QBs coming out lack experience as something as basic as taking the snap under center or calling a play in the huddle or at the line of scrimmage. Most of the spread QBs haven't even worked a full route tree. When it comes to spread offense QBs the best NFL scouts can do is scout athletic ability. That makes the difficult job of scouting college QBs much more difficult.