Oh definitely, there's a limit to what can be expected.

But then there's a difference between tourists trying to make themselves understood through a combination of Lonely Planet handbooks and hand signs and a guy with B1 proficiency. And a tourist trying to find Louvre or something similar is probably just trying to be nice about it with their high school French, and not trying to further their skill. In that case I'd say it's fair to acknowledge their effort, but then try to give directions in English. Since there's probably good chance they'd get lost if you try in French :D

But I'd say, for my own country, people could be much more accommodating to language learners. And that's more the point I tried to address. But it of course requires a certain level of skill, before you can reasonably ask people to talk with you in your target language rather than English.

And no, if you are hurrying home from work at 17.30 I dont expect you to get home late for dinner because some random dude wants you to explain the different French prepositions.