That's a design philosophy that may appeal to you, but it doesn't appeal to many others, myself included. I'm not playing a game to be challenged, I'm playing a game to immerse myself in fantasy milieu to escape my own reality. The worst possible thing I could think of when playing such a game is to be pulled out of that blissful ignorance of the real world because *I* have to do something like solve a bloody riddle, or charm the king, etc.
Roleplaying is great, but it's my character that should be the star of the show, not 'me'.