I have said for a very long time the biggest problem with the zone read is that there isn't a third option that stretches the defense to the side lines. Basically, in the normal zone read play, the defense just needs to contain a little wider than the tackles. If you have that other pitch man that is a threat for a pitch after Taylor keeps the ball, then it just makes it that much harder to defend.
Athletes, especially at DE, can kill the zone read. The problem is that the QB portion of the zone read is a backside running play and because of that you have potential free defenders. That's how the scrape exchange works. It takes the 'read' out of the play by having the DE always come down the line, with the backside LB scraping to take the QB. It can be countered in numerous ways, but by taking the quick and dirty method of the zone read out of the equation it killed off most of the reasons that teams put the play in to begin with.
What we're talking about with so many options in the backfield is being done. Oregon has used a modern day version of the wishbone. But even with the frontside zone blocking in place, the defense just keys on the heavy flow in the backfield and reads the play. The play devotes so much to backfield distraction that it simply runs out of blockers, so if the DTs can slow down those combo blocks then the backers, both front and back, have little to worry about.
It can, however, make for a great passing play because you can freeze both the frontside and backside LBers so easily. The defense, in essence, just parts in the middle for you. Obviously you can throw a lot of screens and such into the play as well to create width that way.
Lots of good options, but one has to be careful of them. Like any counter play, the real benefit is to allow your flow to create a number advantage on the backside for you. Adding options to the backfield, or backside receiver options, etcetera doesn't necessarily solve the problem solutions like the scrape exchange have caused for the zone read. It's biggest advantages are that it is a backside complement to the zone packages out of the gun, it's easy to install, and the reads were simple. While we can create these alterations to the play, and it is fun doing it, that's a serious amount of time to devote for any team that doesn't use the zone read as a big time part of its playbook. For most teams, that wasn't the case and as I alluded to above, that's why it's not run as much as it was.