Any time I encountered a rule that seemed strange I would ask my closest Japanese friends (girlfriend, her parents, friends) and they always gave a reasonable answer that almost always was related to the rule upholding collectice civility, safety, or productivity. And they happily acknowledged the possible drawbacks and were willing to consider if the law was actually good.
Another thing they value is to not make change until one is certain it is actually an improvement, and they assume existing rules were made with the same care. The above can be very frustrating because there's some changes that are obviously for the better and some rules not made with the best intent or carefulest consideration.
But the idea that Japanese are all cowards dismisses that the demure personality comes from a collective cultural agreement that requested change must be thoroughly considered, and that it is in some way implying the previous makers of a rule were unwise or lacked consideration. So to propose a change without being what they'd consider a brute or idiot would take maybe more energy than that person is willing to give for the issue.