It's life-threatening. There's not enough air up there to support life. It's cold, colder than human beings were meant to have to endure. The weather is unpredictable. One false move, and you're done for... one slip, one misjudgment, one act of hubris.
The people who choose to make the climb do it for the craziest reasons, some of them. For some it's an act of arrogance. For some, it's the logical thing to do with all their money. For some, it's a spiritual quest. For some, it's the last significant decision they will ever make.
Succeed or fail, and it's one hell of a public success or failure. Succeed, and it's almost never due to your own skill or intelligence entirely-- other people help, guide, sometimes even carry you. Fail, and it may be your last opportunity to do so. And you can be sure-- if you fail spectacularly, people will make money analyzing the spectacle of your failure for years to come.
I'm just not sure why anyone would do it. But I wish them luck. All of them.