I was also pretty disappointed with what came in the package. You would think they would have made the game at least somewhat different or with some added features. It's just a straight port of the SNES version. Lame.
But it wasn't anything surprising if you're familiar with Nintendo's marketing tactics. They saw an opportunity to cash in on the anniversary and they took it without much effort. The price was right in comparison with standard Wii games so you can't really complain. If it had been $50, then there would have been some pissed off customers including myself.
We always ask ourselves "Why?" when Nintendo releases certain games and consoles, but we buy them anyways (most of the time) because it's Nintendo. A Nintendo product may lack substance or validity, but it's almost a culture to collect and enjoy whatever they put out.
I do think they go a bit overboard with "updated" handhelds. GB, GB Light (JPN), GBP, GBC, GBA, GBA SP, GB Micro, DS, DSL, DSi, DSiXL. I mean seriously? How many handhelds do you really need? I think the DSi and DSiXL were a waste. I admit, I traded up for a DSi when it came out, but it was disappointing. I was thinking, "So it's a DSi with a two cameras that serve no real purpose? So this is all the content they have for DSiware?" When the DSiXL came out, I was thinking, "So it's a DSi for people who can't see well that have big hands?"
I'm glad they are finally coming out with a "new" handheld with the 3DS. Though, you know they are going to do like 3-4 variations of it as well in a span of 10 years. And we're all going to buy/trade for them.
To Matt's point, I hope they do come out with Zelda and Metroid anniversary sets. Maybe they will be better since there was never "All-Star" releases of those franchises so they'd need to develop and think it out a bit more than just port a previous release.