You may very well be simply failing to understand that there are important cultural differences between the French and many other people, Americans in particular.
The French tend to greater formality than Americans or Australians (to name just two). They find the immediate assumption of friendship or the sharing of personal information with strangers to be intrusive and even offensive.
The French are taught to be intellectual and to value debate, even argument, about things like politics and will happily engage in lively and opinionated discussions that Americans in particular seem to shun. Especially during the Bush years many Americans took offense at the active dislike for his policies that were prevalent in France and frequently voiced.
The French are quieter than many other people and dislike loudly voiced conversations. In a restaurant you can always pick out the Americans because they seem to say everything at the top of their lungs.
The French dislike ostentatious or vulgar display. People with hot pink toreador pants and purple tee shirts with "cute" sayings emblazoned on them are almost invariably tourists. You'll notice the heavy emphasis on neutral colors and plain black and white clothing among the French.
The French find the habit of many to natter on about the price of their possessions and the extent of their material wealth to also be vulgar.
This is just a partial list but you can see that it is not necessary for you to say much or even anything to be doing something that will offend.
Perhaps because the France is so well known in other respects and French culture so influential in many fields, foreigners, especially Anglo Saxons, assume that there will be few differences in social conventions.
If you were in Borneo or sailing up the Congo you would be aware that you were in a different culture from the start and perhaps be more careful not to offend. But the same rules of the wise traveler apply in France as anywhere. Be sensitive to behavior of the people you find yourself among. Take your cue from their actions. Always remember you are a guest and act accordingly.