If having one over the other is no excuse then why did Bandai give us this thing that resembles a VF-25? Surely a bigger company can do both but they took the easy way put and just went with it being durable (which is still unknown). Yamato's selling point is their accuracy. If they made their toys more durable and less accurate, that would go against their selling point. Sure it would be more balanced but it would make it just a mediocre product with no selling point.
If all of Yamato's valks had the ugly proportions of the DX VF-25 and was more durable, would people be happy?? Their accuracy is what makes fans want to buy them. If their products were less accurate and their QC problems were unknown, would the same amount of people buy them?
When I get a model whether it's a toy or kit, I want it to LOOK like what I see on the show. And since QC problems are often times unknown until you get it, the product has to look damn awesome for me to be interested and buy it in the first place. If it doesn't look like what I want I simply won't buy it regardless if it was indestructible.