I've worked out why armoured knights were considered 'honourable'

[baloonworld]

Through wearing armour, they were able to give the impression of an external skeleton with jointed appendages, thus cleverly disguising themselves as arthropods. A similar phenomenon was observed in feudal Japan, where due to the island's lack of metals, the warrior caste wore masks that resembled a certain species of crab.

If these disguises were done in an honest attempt to approach the physical form and hence spiritual essence of the crabs, or if it was a less worthy attempt to order to gain the respect accorded to arthropods, the result was the same: in the popular imagination, these noble warriors are accorded respect worthy of an arthropod.