Then he's doing it the wrong way.
This is business, not some feel good **** where everyone gets a trophy at the end.
You fire his *** now. It doesn't have to be mean, he's getting paid to leave. You simply say the results speak for themselves and it's time to part ways. You don't have to say anymore.
Instead, he'll keep him however long or maybe Mario is truly dumb and we keep him another year. The players have their own issues and problems, but we're doing absolutely nothing to build them up or make them believe it's going to get better. They might be coaching them, but guarantee they aren't listening or improving. Nothing is being accomplished by keeping him at this point. It's affecting both sides of the ball.
Want to have a bad culture, keeping someone this ineffective around is how you create a toxic environment.