“Either blocking below the waist is dangerous or it’s not. It’s not anymore dangerous five yards down the field than it is on the line of scrimmage. If it’s that scary, they ought to not tackle below the waist.” - Paul Johnson
This is kind of a nonsensical comment.
It's clear that the rules committees think blocking below the waist is dangerous. They are literally flashing a red neon sign that says "Blocking below the waist is dangerous. Don't do it!" (I'm not saying I agree. I'm saying the message is pretty obvious that they think it is). They decided to give Tech, and other 3O teams time to adjust by only making it illegal beyond 5 yards right now. It's likely going to change soon.
The alternative wasn't it's legal beyond 5 yards. The alternative was, as CPJ seems to be wanting, that it's completely illegal, which would have only screwed Tech and the academies without giving them any time to adjust. The discrepancy in the rule as implemented is clearly intended to give existing teams reliant on cut blocks time to adjust. To complain about that seems counterproductive at the very least.
Also, I have to disagree that all cut blocks are the same. There's a huge difference when you're a D-lineman expecting a cut block off the snap and therefore able to find a way to evade it, and a linebacker running towards the edge and having someone cut you below the knees along the sidelines, without a dead period to position yourself to prepare for it.