It's not about whether or not you need to use them. You can't. And it's kind of funny. One hundred years ago, a guy introduced the concept where instead of trying to remember how often a guy got a hit he actually calculated the rate at which it happens. Then some older guy said, "Who needs that, I can tell who can hit and who can't with my own two eyes", just like you are doing now.
It's even funnier than that. You piss and moan about the decisions they make and want answers. Well, go get them. James started it all, and he works for the Sox. So, while you mockingly question its utility, the answers are within. I suggest you start with Bill James' Historical Baseball Abstract. It's not heavy on stats but you get a feel for what he started and why, and you'll see he's not just some number cruncher. He's passionate about one thing. Baseball. And his books have a breadth of knowledge about the game from its inception to the present.
And, can you quit with the non-sequitor about me thinking its only about the stats. I've never dismissed the importance of scouting. I just choose not to ignore something because it is new and unfamiliar.