I'm visiting Paris fairly often and my French (Swiss German school french) can easily be described as rotten. It's serviceable enough to buy a carnet of metro tickets, or to ask directions.

I noticed, however, that it's highly appreciated when I try to speak French with Parisians and I very rarely get snide answers.

I observe this actually in almost every country. Try to speak a few words of the language and you're usually rewarded. (And compared to my Czech, my French is easily on Camus level).

I think one of the issues is that the French are especially touchy when it comes to language and radiating an attitude of "Are those natives actually to dumb to speak proper English" definitely won't win the French over.