People will always use the image they have of you. You can't protect that. No laws can do that. But that image is not you at all. And it's free to use as one would like to. If you are worried what people will do to your image after you're dead, you should make your image something holy beyond doubt, but that wouldn't be you now would it? Why be troubled by what people might think of you? That's a very unhealthy way to live you life.
A life has ripples and consequences that can be felt long after death. If you can somehow shape those consequences in advance, wouldn't you like to? If your "image" is open to all then you could end up having horrible organizations use it to propagate horrible things. When you have the ability to bequeath it to someone(s) in particular your image is less likely to be used in ways you would find harmful. I see it less as something a person is bothered by because it effects their image/brand but more as something a person is bothered by because it could be used to help nefarious people/organizations. Edit: View it as capital. If you had a suitcase full of $million dollar bills upon your death bed, would you want anyone to be able to grab a fist full? No matter if they're murderers, rapists, saints or volunteers...? No, you'd probably have a preference where that capital was allocated. Your "persona" or "image" is also a capital producing mechanism. You should be able to allocate it how you see fit.
Wether your image is used for good or evil can't be protected by laws. Laws are always changed, reinterpreted and broken all the time. If you have any insightful ideas about the world you should share them in an unambiguous way, maybe write a book, film a documentary, have a speech on TV. If your image is a "capital producing mechanism" and you have a suitcase full of millions upon your deathbed, you are either stupid not to have spent it during your lifetime or unable to handle money and you deserve to be falsely represented.
Yeah, the suitcase was a metaphor. As for your likeness being used, imagine that your a singer and after you die some shitty band starts using a hologram of you on stage with you as their lead singer. If you were able to leave the rights to your "image/persona" to your estate (family) they could protect such things from happening. Thats all. What do you see as the downside from allowing this?
You could allow it, but it wouldn't do you any good. How do you trust your estate? Which part of your image will be "protected" and which won't? As a former fellow artist I have issues with IP laws. If you want your songs to be heard than you should stop regarding them as intellectual property. If you want your audience to pay for hearing them, you should not be wondered when they tell you (or pay you) to shut up. People are getting used to the idea that all information is free and privacy is history. So why do we still pay for music? To shift the gems from the garbage heap we will pay a finder's fee and when we're hooked on something we will support that something. The best example I can give is the Kickstarter project by Amanda Palmer which got her 1 million dollar in a week to produce an new album. Crowdfunding is the way to go.