You didn't play this game back during the NES days, did you? This game was so good it's one of the few NES games I remember at all from my very early youth. A remake of a very old but very good game? This isn't nostalgia because of DuckTales per se, it's because this game was a shining gem of the console.
The reason they are remaking old games is because there's a niche in the market for people that want to play games that played like older games, because game design has shifted since then, not necessarily for better or worse but because of the general trend over time. Point-and-click adventure games are also making a slight comeback (see TellTales's success on that front along with various indie groups). Look at how many Halo-esque or military FPSes are released these days and tell me that this isn't something of a breath of fresh air.