Laws are legitimate so long as people freely accept them. When the laws become oppressive, people revolt. Laws cement communities. People can reduce the number of laws but must obey the existing laws. People generally observe legitimate laws even when there’s no threat of punishment. Legitimate laws can be arbitrary to a degree (65 rather than 66 miles per hour speed limit), but reasonable overall. A person cannot morally or legitimately refuse observing a law, though he may campaign for changing it.
Jews may and should call for changing the rabbinical observance, but as long as no new consensus has emerged, Jews must follow the age-old rules. Ancient people correctly equaled antiquity with truth; test of time is the only way to prove a system working. The Jewish law which preserved Jewish people for millennia, is proven working. Jews can keep changing it slowly, testing new laws, but not recklessly abandon it or, even worth, tolerate individuals’ disregard of the community’s legal backbone.