Why did Riot not learn from the last OFA?

The last URF mode got updated, including outright permabanning some champs and introducing a ton of balance changes. Why exactly was this not done for OFA? Why did they not learn from the last OFA the same way they did URF?

Here's how the heirachy works: If Fiora is picked, that team wins by default. If an ADC that is not GP/Darius/Fiora is picked, that team loses by default (400 armor too stronk). Assuming neither of the above, if an AP with a non-ult stun is picked, and the enemy does not also have a stunlock champ, the former wins by default.

No dealing with thornmail unless you abuse the fact that over half your damage is true damage (as Darius / GP / Fiora). And no reductions to CC length so you aren't casually permastunned.

Not exactly what one would call fun.