i think the whole point of the subject is all about trying to teach law in context and its place in society, by highlighting the issue of what the law is vs what it ought to be,In thinking about the law making process, for example in theory Parliament sometimes writes laws based on the lobbying and influence of certain people.
The law claims to be fair(moral) and just but is that so in reality or do policy issues and the need for stability ,sometimes take precedence over law being just , However, imprudent or even stupid laws are they are still valid.To think about the law not as just rules and principles but its purpose or what it should be(positivism vs morality) is i think the essence of jurisprudence and i think it is worthwhile if you engage with it