Balancing is what led to the homogenization of all classes. It made the gameplay sterile and stale.
Instead of focusing on making the classes feel fun, on giving them flavor, they focused on balancing. And as as inevitable result of that, we've seen pruning and standardization of abilities and all classes ending up playing the same like all others. Each class now has a button for X, a button for Y, a rotation that builds a resource and spends it etc...
I'd take an unbalanced but fun game over a standardized and homogenized but polished turd any day.