It's quite different here. This is an accessory wholly and completely dependent on the intellectual IP of Hasbro/Takara. It takes their IP in the form of a character and produces a product that predicates its success on that character. Look at the colour scheme, look at the successive weapons sets. They all go to confirm the very same thing. It's not like a general transforming toy or accessory. It has its success completely based on its likeliness to something that does not belong to them.
A car has many makes, many differences. Transformers are purely and completely the property of Hasbro/Takara. To produce an item whose appeal is completely dependent on the IP of Hasbro/Takara is where the transgression
As I've put forward before, if the armour hadn't even remotely resembled Ultra Magnus, would anyone have been interested? I think not and therein lies the transgression. For custom accessories, it becomes even more obvious in the case of something like the Grimlock's crown, that directly competes with something Takara intends to offer.
I'm sure each of us would appreciate it even more if we were the ones in the position of Hasbro/Takara and someone produced something that directly competes with what we created in the 1st place, something we put the money and time investing into or takes away an opportunity to produce something ourselves. We'd be pretty upset.
And again, don't get me wrong, I'm not in favour of KOs by any stretch of the imagination. But the ground we're treading on is one and the same - the ripping off of someone's IP, IP they've developed over time. Just b/c we like the product doesn't make it necessarily acceptable and how can we condemn one and not the other when fundamentally they both exist b/c of the same transgression? So we need to rethink our position on the matter as landscape of TF collecting changes and more and more custom products are made.