Why continental Europeans (including Britain) have not won more rally Sweden can be explained in other ways than blaming snow.
I have already explained why Carlos, Colin and Didier did not win and argued that there were other rallies than Sweden they did not win in too.
That Loeb does not win more Rally Sweden is due to the car, most likely. Citroen had a large tire wear when a lot of frozen gravel appeared. Ford was almost always better on slippery roads, both on mud and snow. Loeb won one of two opportunities to win rally Norway
When Petter went to Ford in 99 had relatively little experience with snow (few rally), from then on, he drove (like almost everyone in WRC) only one race on snow per year, Sweden. Even he managed to win this rally once (like Loeb). I will dedicate this victory with great help from Mækinen and Pirelly, not much experience on snow. The fact that Mækinen, Grønholm and Latvala have had Sweden as their favorite rally (in addition to Finland of course) have also not benefited South European victories.
In addition, we do not need to explain why Loeb and Ogier have won rally Britain 7 times, while Tommy Mækinen never won there.
And if you think Latvala and Mikkelsen have many years of snow experience, you're wrong. They started driving in Great Britain when they were 17 and have run around the world after that. Ogier who has won many Swedish does not have this experience either. But what they have is extensive experience on varied road surfaces.