Let me get this straight...the scheme that Golden and D'Onofrio run doesn't allow DT's to get off blocks and stop RBs...it doesn't allow them to read pass and get to the QB. Right?
It allows them to stop the RBs at the LOS (or 5-10 yards down field, since we routinely get pushed back while trying to hold blocks at the LOS) while holding their blocks compared to allowing them to shoot one gap right off the bat, avoiding blocks, and getting into the backfield. Hence, TV's quote about letting the OL hold him.
Stopping the ball carrier at the LOS is not the goal of 2 gap technique -- it's actually a drawback. The goal is to have an overlap of gap responsibility. To understand why an overlap of gap responsibility is a good thing, we must first understand gap control, or 1 gap defenses. 1 gap teams assign one player to a specific gap with the exception of a couple positions, usually two linebackers, who have two gaps -- which themselves overlap but are consecutive.
A very basic example of this would be a 44 defense. Outside linebackers play D gaps, defensive ends play C gaps (if TE in the game then one end plays a 6 tech, which sort of works as a 2 gap technique), and defensive tackles/inside linebackers play alternating A and B gaps (3-tech is in B gap and Nose is in A gap). The two inside backers have somewhat overlapping gap responsibilities. The strong side backer has strong A gap and strong C on run to and weak B on run away. The weak side backer plays weak B and strong A, based on flow (it's a much easier position to play).
In a classic 52(34) the defensive line plays head up techniques (4 for the DE and 0 for the DT). The linebackers are doing the same from a stacked position (30 stack or 30i). the OLB's are outside shoulder of the end man playing a single D gap. The defensive line and inside backers all have two gap responsibilities. Defensive ends: C & B, Inside Linebackers: B & A, Nose: A & A.
One error in a 1 gap defense means huge gains, and you'll also always be one gap short in a 2 shell, which is another possible point of failure. One error in a two gap defense means no gain. Two errors in a 2 gap defense means big gains. A 52(34) is very challenging to learn, but if done correctly with the right personnel then it is unstoppable -- theoretically.
Say what you will about the players and coaches. I just want people to have a better understanding of what is actually going on.
BTW we are not a pure 34. We 1 gap a lot, too.