Yes they are, and as a French Canadian myself, this is my perspective on the matter:
- As opposed to other euro languages whose colonies eventually became more influential than the old euro country, France remained the centre of the world for francophones.
- France is an extremely centralised country historically and currently as well, so that within France the standard will always be Parisian French.
- For that reason, all the people from the former colonies (except Canada/Québec which were cut-off from France in the 18th century) learned Parisian French.
- France has esssentially killed its regional cultures in its centralistic approach. A couple of centuries ago, various languages were spoken in France, for example Occitan, Breton or Basque. But the government actively weeded out these languages by imposing French at schools, etc. Hardly any young French person nowadays speaks their "ancestral language" as good as they speak French, except perhaps in regional strongholds like Corsica / Basque country. But even then, the norm is that even in Corsica, young people have a better command of French.
- Regionalisms tend to be snobbed in France, so that in educated Parisian circles, you will rarely hear somebody with a strong regional accent and standing out as a non-Parisian is often seen as embarrassing by French people, when they are outside of their region. Try to imagine someone speaking with a Marseillais accent in business meeting in Paris with a bunch of lawyers / bankers. The Marseillais would not even be taken seriously.
- Culture/education/intellectual sophistication is extremely important in French culture (moreso than in any other western culture IMO), and the French language is a very codified medium for this culture, so that speaking "properly" is extremely important in French culture.
- Lastly, and this is my own, very French Canadian point of view: snobbism / elitism / pedigree if you will is very present in French culture and language is one of the most critical conveyor of pedigree, so that yes, for that reason and all the other reasons above, French people are very judgmental of language and make fun of us since many of us do speak like absolute ass.
- Lastly #2: I need to stress that most French people tend to be very kind towards and like French Canadians nevertheless, even if the arrogant French sort of ruin it for the rest.