The problem with the sanctity of spoiler is that some movie only worth their final twist.

This is wrong-headed and dismissive of storytelling in general. You're effectively arguing that the only "good" stories are those that you can read the Cliff's Notes first and enjoy equally. In effect, you're arguing that unless a tale remains interesting while mediated by random strangers, it isn't worth experiencing.

I'm not a fan of Shamalyan but 6th Sense is a tight little tale. It isn't about Bruce Willis, either - it's about Haley Joel Osment and his ability to channel his fearful powers into a force of good. Bruce Willis' pulse is a subplot. In fact, it wasn't until the 7th rewrite that Shamalyan even figured out that Bruce Willis should be dead. Now - of all the writing I've done, only one story has been through six rewrites. Without getting into the objective measurement of art, somebody saw something in that tale prior to The Late Bruce Willis to drive Shamalyan into hacking at it again and again and again until it was the story that got shot (which was, if I'm not mistaken, the 13th rewrite).

You can like it or not, as is true of all people and all tales. But arguing that the only reason it's worth watching Sixth Sense is to find out why Bruce Willis has a weird relationship with his wife is... short sighted.

Kind of like arguing that every viewing experience is unique. Sure. Of course it is. But its a whole 'nuther thing to argue with a straight face that there's just as much difference between the second and third viewing of something as there is between the first and second.

You can make these arguments. But you can't make them well. You can't make them make sense. And you certainly can't make them compelling.