Forcing everybody into a single, homogeneous culture dictated by a central authority is a recipe for disaster.
People often point to the chaos that takes place in the US government as a 'failure of Democracy'. I'd argue the opposite, it's a side effect of a successful Democracy that supports a wide variety of subcultures with different beliefs/norms.
It should be extremely difficult to establish a universal consensus.
The danger comes when the central authority makes declarative judgements that affect everybody without working out foing due diligence. Some topics can't be addressed globally and therefore should be defined locally or not at all.
Universal laws work best when they're used to guarantee basic human rights and freedoms. Unfortunately, some groups try to manipulate public opinion and garner support by attaching 'human right' to whatever particular pet cause they're trying to force.