Christianity = Tylenol for Life's Problems?

I've noticed that in traditional conservative circles the "Good News" seems to consistently carry a theme.
The theme is:
"Become a Christian because your miserable and He'll fix all the mess in your life."

Why can't the theme be:
"Become a Christian because your a bright lad and will find enlightenment!"
"Become a Christian because we believe sciences are a valued part of human knowledge and the bible screams science!"
"Become a Christian because you will learn the truth about how people tick. Gee Wizz! You've got the ear of the creator of humans! He created philosophy/psychology!"
"Become a Christian because you will find a purpose that so much more exciting then desperately trying to make yourself happy!"
"Become a Christian because your missing out on an amazing opportunity to fight tooth and nail for something worth fighting for!"
"Become a Christian because... "