I would say a better new rule would be to require ATC to specify the hold short when the taxi route crosses the active runway, that way there is no confusion as to whether or not the runway can be crossed. In reality, I have always heard ATC doing this, even though it's not required.

While not knowing the rule as it exists is not really an excuse, I think that if a good number of pilots don't understand it, it's worth changing in the interest of safety.