The lady doth protest too much Why Should I Care
Why Should I Care?
Blood is thicker than water, which is easy to see when it's spilled all over the floor at the end of the play. Hamlet dwells on issues of incest, which just might be taking the familial bond a little too far, and hinges on Gertrude's actions.
You shouldn't have sex with your family—pretty much everyone can get behind that—but maybe, Hamlet says, you shouldn't be murdering for them, either. So, what's left? Normal families? Nah. This is Shakespearean tragedy; keep looking.
That's really the whole point of all these antics, isn't it? Drama, drama, drama. Hamlet could just kill Claudius and be done with it. He could confront his mom about what she knows. But he'd rather have the drama of it all. And we'll admit, so would we. We won't be protesting too much to that.