See, you're missing the point. In Mr. Driller I can just press down and keep digging over and over again. Sure I won't do well or get that far but that's still the way I can play the game. Same thing goes for NG. You can just use the same few moves over and over again, and you might even be able to beat the game, but it'll take you a long time to do that and you'll struggle because you'll have to continually get more gold to buy potions from getting hit so much. Just like Mr. Driller, to play NG well requires constant concentration and adapting to the situation at hand and using the tools and methods that suit your play style.
You're incorrectly making a statement about lack of depth by saying because you don't *need* to use the full arsenal of moves and abilities that they're totally useless. The fact that people can make it through the entire game without getting hit and others can barely make it to the end is evidence of its depth. One last example. In VF I could make it far by just pressing PPP over and over, or cheesing the same combos all the time, does that mean the game doesn't have depth? I think we'd both say no, because the skills to become better are there for those that look for it. Just like NG, and just like Mr. Driller.
So sorry, your comment about depth doesn't hold. So I ask again, why is NG repetitive and not other games?