The maxims of battle dictated that practical functions were the most important on the battlefield. Something like a beautiful outer appearance wasn't even worth considering.
While a humanoid mecha may seem awesome, its attack methods were actually rather limired. Since it imitated the attack patterns of a human, it was easy to predict and defend against, and since it needed to maintain its balance while walking, a great amount of development resources and parts would be spent on balancing the mecha.
This was doubtlessly a critical amount of waste, especially when the technology was still immature.
But then what type of combat mecha was the most efficient?
"It needs plenty of space for firearms, so the best way is to have many individual sections that can contain more weapons and parts!"
"Let's abandon the walking mechanism that's just a waste of resources. As long as it can kill, it's fine even if it crawls on the ground."
