If you have to ask why, then its probably not for you ;)
If it doesn't appeal, it never will. Some people are instinctively attracted to the world of miniatures and scale modelling, and some people can't imagine a bigger waste of time. It's the same with, say, cars - another passion of yours I believe, Tarrakk. I, for example, can appreciate the aesthetic and technical aspects of motor vehicles in an intellectual sense, but they don't exert any kind of hold on me beyond that. I can't even drive, and have no real desire to do so.
Warhammer, and miniature wargaming as a whole, is a largely unproductive activity, like almost all hobbies, but it has to recommend it at least the fact that you tend to end up with a tangible, physical reward for your efforts. Most computer games are necessarily ephemeral - one the game has been played through, there may be some replay value in trying to achieve "100% completion", or unlocking new characters, guns, vehicles, outfits or whatever else, but I don't think any of that can compare to the sensation of having a completed army on the shelf.
Wargaming is an activity that rewards investment of time and money. You don't get instant gratification. For most, it will end up being a largely solitary hobby - most of us spend more time painting than we do gaming - and it will never be "exciting" in the way a computer game, movie or even a piece of music can be. My best friend dabbled in 40K long before he ever met me, and never pursued it much because he thought the game lacked enough interactivity. He said to me once, only half in jest, that it would be better if the figures "actually moved around and fired their guns at each other." He has a short attention span.
So, ultimately, you either "get it" or you don't. You're never going to persuade a kid who doesn't want to play Warhammer to do it. I think there is a segment of the young market that get into it through peer pressure, who dabble for a year or two like my friend, but mostly the tactile enjoyment of the toys (because that's what they are) wears off when beer and girls come calling. Some come back (I did), and some don't.