Yeah, but how many people in the demographic for this DLC haven't played those VC games? If you own a Wii and haven't played Mario 3, unless you bought the system yesterday, why the hell haven't you done that yet?
Have you used the Wii's Virtual Console? lol. The obscurity and inaccessability of the Wii shop is one very good reason why such a situation might occur. I have quite a few friends and family members who have owned a Wii for years and for whom the Wii Shop is a website on their Wii where they can look at tiny images of old video games, lol.
However, several of these people have already downloaded games on eShop because it's simply more user friendly. So they're in the market for DLC but have not played Super Mario Bros. 3.
That aside, the example I gave was of course largely theoretical. For the purposes of comparison it's always better to contrast two things with everything else being equal. With everything being equal (in other words assuming that you've never played either) SMB3 is a better value proposition than this DLC level pack.
That's not exactly a controversial statement. Hell, I would argue that Super Mario Bros 3 at full price is better value, but then again it's one of my favourite games.
You know what? That got real pedantic real quick.