Unless I'm reading the explanation completely wrong, that's not exactly true.
If they build All Madden so that we're facing Robo QB who throws 90% of his passes over the middle for a high completion %, we're stuck with him doing that. The only way to bring down the CPU's passer rating is to play at the lower levels, which means you'll be facing basically no defense or anything.
It just seems like they're assuming they've put together the perfect game and there's no need to fix the CPU's sliders. Feel free to correct me if I'm wrong, anyone.