I believe there are several reasons for this:
Wii games generally sell at a slower pace than HD games. Many/Most HD games will have sold the majority of the copies they will ever sell within the first 4 to 6 weeks whereas many Wii games continue to sell for months and months and (eventually) sell past milestones which people thought were unreachable.
Although Starwars is a very mainstream IP, in a large part because it has been used in so many quality "core" games, it is much more popular with the "core" demographic than it is with the more mainstream gamer. Although there has been tons of Starwars shovelware, very few discussions of the "Greatest" (or most "Important") games ever get by without listing at least a couple Starwars games.
Publishers are posioning the waters with their lack of effort on the Wii. The other day I overheard someone talking about how they were not going to buy any Wii games that were also being released on the PS2 or PSP because those games are built around the limitations of the PS2 or PSP with tacked on Wiimote controlls that don't work well. This was not said by someone you would expect to read reviews or troll webforums, and if this mindset becomes more common publishers/developers may have really screwed themself.
