Kit makers almost always use EC1118 yeast for two reasons. 1. Like was already said it has hiiiigh alcohol tolerane, and is almost impossible to have a stuck fermentation, and 2. It is a very neutral yeast that won't do very much pro or con to the varietal that it is used on. By using it, they are making about a bullet proof as they can for the novice.
That being said, 1118 is probably not the BEST yeast to use in any wine. Yeasts are cultured for their effect in specific juices, and the best yeast to use on a wine depends on the varietal and your personal profile of what you want and like. While 212 will do a better job than the 1118, I would probably like a BDH or X, or Syrah, and possibly AMH. If you want to make the BEST wine, then substitute the EC1118 with yeasts that are specific to the varietal and your preferences. If you want the good, bullet proof wine, and don't want to spend the little extra, then stick with the EC1118, it will still make good wine.
morewinemaking.com has a great selection of yeats (more than the local LHBS) and a great discussion on each yeast. If you want to really get the best of the wine, even consider using multiple yeasts to enhance different characteristcs of the varietals. They also have a great tutorial on their site about multiple yeasts and blending.
Sorry to be so long winded, but this is a topic close to my heart that I lecture on all the time. Unfortunately most beginning (and even some long time) winemakers still think that all that yeast does is produce alcohol.