I don't get it

[tcannizzo]

There is already a prescription for safety with the double base.
If a throw is coming from foul ground to 1B, the defender is entitled to use the colored portion of the base. If this occurs, then the BR/R must use the white portion of the base. This puts the onus on BR/R to avoid INT/USC from a collision/crashing perspective.

So, what do we have if an errant throw from F6 brings F3 down on the colored portion of the base and BR collides with F3? Are you going to rule INT/USC? I think not, because there would be many cases where BR would have had zero time to re-act to this.