Yeah, I think it can cripple them, but there are almost always ways to turn off the setting or avoid it so that it doesn't cripple your experience. For example, in Zelda, the "Sheikah stones" which basically give you hints on what to do can just.. not be used. The EXP share in Gen 6 can be turned off and O-Powers don't have to be used. Fire Emblem plays can choose Hard / Classic instead of Easy / Casual (I would like to note though, without Easy/Casual I probably would not have gotten into FE, because I suck at those types of games, and for me being able to play through the game once easily allowed me to get a hang of things and beat it on Hard/Classic)
Okay, also, reading this thread I do think there are plenty of examples where it does cripple the game =/ I haven't played DK Returns but my brother has and at parts isn't there an option to have the game play for you for a certain amount of time or something? How is that even considered beating a level, haha.
I just think it's really hard for gaming companies because when making games for popular titles they now have to appeal to a wide range of fans (specifically, I'm talking about Mario, Pokemon, Kirby, etc) ranging from older kids like us who are experienced, kids like my brother who have played games before but aren't the sharpest, and kids who are still new.