Let me try again:
The previous CEO of the story wasn't wrong about what's important at all. Only about how much time it takes. He considered everything important and maximum priority, but didn't believe the "previous thing" was taking 80% of the time of the team. I couldn't tell the team to "drop the previous task" like the other post suggested: it was also maximum priority.
"Important" and "Takes too much time" are very different.