It is, he's failing at managing his players against a 10 man team most people have never heard of in order to finish the game with a win.
He failed failed against City
He failed against Chelsea
He failed against Atalanta
He failed against UTD
Let's be honest here, has there been one single game this game where we've actually looked comfortable, like we actually deserve to win ? All the games we've played we've looked garbage and without any passion and that's all on Koeman
He's literally the polar opposite of Martinez, always moody, never happy with a performance and vocal about it... But they both gave us equally torrid results. If Martinez was the Yin Koeman is most definitely the Yang
We need a manager who is in the middle of those 2 attitudes, one who knows when to give praise and when to throw the book to motivate the players