Not sure why it's so bad to mis-pronounce a word from a different language when you don't speak that language. Even in the US each region has different ways to pronounce certain English words. It doesn't bother me if someone doesn't pronounce a word "correctly."
My family is from Hawaii and although we don't expect people to pronounce most of those words correctly,it is a litte funny listening to people pronounce Hawaiian words. Of course, when my wife (who is from Iowa) does it I think it's cute
One of my uncles, who works in the tourist industry, loves to give directions to tourists and say the street names really fast. They all get a good laugh and he then will write down how to get to their destinations.
When I first lived down on the Gulf Coast, I butchered some of those cajun words, even after being corrected 100 times, I just couldn't get some of those words right.
I just don't think I can bring myself to start pronouncing "Saison" with that nasally ending to it. I'll stick with saying "say-zahn," which is how people I know here in Denver say it. Now if I ever move to France...