I don't think Vice City Stories suck, It's quiet fun to play around. The Graphics have improved only a bit but the gameplay is still the same as Liberty City Stories, accept with the new movements they make in some of the cut scenes.
Even if they did make San Andreas Stories, atleast they might improve it a little more so it turns better, and has anyone ever thought about the word 'Development'? They almost use this in all the games they made, They Developed GTA Vice City, and made the graphics better, they would do this to all games, so it's not the same Graphics. So when GTAIV comes out, the graphics will be improved alot then San Andreas did.