Battle clerics get a bad name because of Dungeon Scaling.
The barbarian runs a quest with his hireling, kills stuff fast enough to be easy to heal, the hireling can easily keep him alive.
The battle-cleric runs a quest solo, does enough damage to complete the quest without much troublecompletes with half his sp bar left.
Our heroes join a 6-man party, all the enemies have 3 times the hp and do 3 times the damage. The barbarian is no longer that easy to heal, the battle-cleric no longer does enough damage to kill fast enough, they both blame each other for being bad players. What happened is that the game got a lot harder, punishing them for running together.
Mostly true assesment.
Regarding the bolded part, The game punished both players for playing solo in a group instead of changing their tactics and adapting to the strengths and weaknesses they both could potentially bring.
Git off mah lawn!
If, If's and But's was Candies and Nuts, we'd all have a Merry Christmas.