For some, I imagine death is preferable to dementia.
I just can't think of a worse fate not just for the suffer, but for those that love them. It is a constant painful and sad reminder for loved ones to interact with them.
I wouldn't wish it on anyone.
Unless you're thinking: you're willing to accept that whether or not you'll ever get dementia in the first place because cowardice or social pressure would prevent you from checking out once you do get the diagnosis. But that's sad and pretty unfair to yourself and others.