Could Turkish intelligence link me to the company if they spent significant resources researching the hosting company that provides services to their political enemies? Probably. Do I have any personal plans to take a vacation in Turkey any time soon, or a pressing need to visit Turkey? No.
I am pretty sure we also have someone, somewhere hosting something that insults the King of Thailand, so I suppose that's a risk too.
If I operate a bookstore physically in switzerland and a few of the books I sell are illegal in france I'm not required to check passports or whatever, am I? I can just sell books to whoever (subject to swiss law) and if a french national illegally imports one to france that's a problem for customs or the local police or whoever (analogously the french ISPs) to deal with. Not me, the swiss bookstore operator.
Now consider if I were handing out pamphlets for free rather than selling anything. At that point I'm arguably not even doing business because no money has changed hands.
I realize that the current legal reality might be that quad9 needs to block french users in practice but the entire thing is a farce if you stop and think about it.
In the Quad9 people’s case, defying French law and still doing operating the services under French jurisdiction might work out just fine for as long as (1) holds true, but it doesn’t take a consorted effort of research to change that. It could just be that some leaked piece of information eventually surfaces. It could be a tweet posted by someone else. And I don’t know how many people work for that organization, or might do so in the future, but it seems like a bad move to make a decision on their behalf to paint a target on all their backs.
Also, France being part of the EU makes being an enemy of the state there seem even more unwise for anyone who might want to have associations in any other EU country.
I personally would do exactly what they are doing: if French people want a government that respects free speech, they had better elect one themselves. I wouldn’t become a martyr to that cause - it wouldn’t help anyway.