Out of those "overpriced" games I've played NSMBWii and DKCR and they are totally worth full price in my book.
Just because you don't see that kind of value in those games doesn't mean that no one does.
I see you liked Minecraft. Minecraft had an MSRP of 26.95 on release . Is that a competitive offering to the games you listed?
At the end of the day, people pay what they think is reasonable, and company's charge what people are willing to pay. No one is being robbed here... the market dictates the price. Economics 101. That's really all their is to this.
That's why I said in OP:
"These Nintendo games sold like mad when the Wii was at its peak, but is it reasonable to expect that trend to continue?"