I have always thought the main argument for/consequence of Hume's law is that just because something is in a certain way, that is not an argument for it to remain that way. E.g., just because homosexual acts were forbidden in most Western countries before the 20th century that is not an argument it should remain so.
Instead, if you want homosexuality to remain outlawed you must produce a moral argument why consenting adults shouldn't be allowed to do whatever they like with their bodies.
But when I read the Wikipedia-article about Hume's law, except for 1-2 sentence(s) in the introductory paragraph, all other examples is quite, or very, different from my understanding of it.
Have I misunderstood something? What is the main point/consequence of Hume's law?