"Verifiability, not truth" means that sometimes we'll put in something
that's
verifiable but isn't true.
If you use IAR now, you'll have a hard time justifying not using it every
time something's verifable-but-false. And if you do use it every time, why
not just fix the rule? (Aside from "it's so easy to filibuster a rule
change and people are so attached to the existing rules that it's impossible
to fix them".)