Whereas college defenses are not keeping up with them. It doesn't make a lot of sense to keep taking 4-3 college players and convert them to an unfamiliar system in today's NFL. So, that leaves two options. Switch to a 4-3 defense as you have been advocating and take the 4-3 college players and put them in a position to play instead of think or draft 3-4 college players for the same reason.
Being that the vast majority of college players come from the 4-3, it may be more productive to switch our defense rather than limit our pool of players that can excel in our 3-4 system.
I know you have argued this before Oviedo, and I am starting to ring this bell as well i think.