Enzymes in the yeast, invertases, convert the sucrose into glucose and fructose. Only by quickly removing the skins, can the Champagne winemakers come up with a white Champagne. Champagne, they just leave the skins in a little longer. Harsh tannins can get extracted from the stems and make the wine harsh, rough, green, stemmy. There is no way of not getting kernels into your red must and harsh tannins can be extracted from kernels also.
Most wine grapes are very small, have thick skins and seeds.
The smaller grapes and thicker skins, the more solids can be extracted during the winemaking process and produce a wine with more flavor and fuller body. Wine grapes are usually also sweeter than table grapes. Whatever differences there are in the flavor of the grape varieties will show up in the wine.