I haven't played them, but NES Remix just seems like robbery. With Retro Game Challenge, even though you did a bunch of challenges on each game, you unlocked the full game. Nintendo's NES Remix are small challenges in hopes that Nintendo will sucker a player into buying their extremely overpriced virtual console games.
From what I know, the first NES Remix is supposed to have over 200 challenges taken from 16 games, and a lot of these challenges are full stages played in specific conditions, not just short tasks. That sounds like a good deal to me for $ 15 bucks. Assuming you still disagree, have you considered the possibility of just not being interested in the concept itself rather than it being a "robbery" ?
And if it incentivizes people to play more NES games, then great ! The NES is full of great games that don't deserve to be forgotten, in my opinion at least, some of them among my favorite games ever. Whether people play them through the VC, track the original games/ports, or pirate them is secondary to me. Either way, there's a lot of fun to be had.