The point of the hadith being used as authority to derive rules is that in fact anybody can misuse them to impose anything he or she fancies. As simple as that.
The question is not whether the hadith are authentic or have sanad or do not have wahtever. The point is that if there are thousands and thousands and are taken to be foundation for rules of law, it sets people at the mercy of hadith magicians who know the magic rules for them in order to issue thaousands upon thousands of uncalled for nor needed rules.
So to admit anything other than God's law is suicide and the law of the jungle.
So if theree are hadith that say sensible things, so profit from them but do not make laws out of them. For that only the Qur'an is authority. And those hadith that do not have anything useful to tell just forget. Why bother with potentially thousands upon thousands of potential rules that only complecate what the Qur'an has made simple?