Why is the MC always kicked out of the hero's party for a stupid reason? Why not a normal reason? Its like the mangaka's cry for help : "I was bullied in school by bad people, waaaaa!!!!".
There isnt a SINGLE manga here where the MC was kicked out of the hero's party for a good reason...its all dumb shit like the hero being a moustache twirling villain or self insert for the author's bullies.
You dont even NEED the "kicked out of the party" reason. You could have the MC leave the party because he wants to retire, wants to travel to a different country, needs to go help out a relative, etc...why go to the extreme of making the hero look bad? It serves no purpose in the story at all. Other than self gratification because the hero is supposed to be the self insert for the author's bullies.