for the love of God!! Only a moron does dismissing a battle oriented healer! FS healers were great but, if the party lacks offensive, another battle type is a must, so a healer that can go swirch to offense is good in any type of situation
mc's problems is he didn't communicate with his teammates properly (yeah his old teammate is a jerk but even here he only revealed his abilities at the last moment, he should tell the girl in advance at least)
..or probably author's idea that it's better to keep them a secret