I'm a born and raised anglophone Quebecker. This is an issue I've faced (yes, faced) my whole life.
There is a great deal of prejudice and discrimination against anglophones in Quebec, both socially and legislatively. Two applicants to the same job, both perfectly bilingual, one Francophone, one Anglophone, most times the Francophone gets the job. I've had people pick fights with me in bars, because I was speaking English with my friends privately. If you didn't attend English school as a child, you can't send your children to English school. I've gotten attitude from merchants for using the wrong conjugation or gender. The language issues touch every aspect of life here and truly divides Quebec. I've been against these discriminatory laws my whole life. In spite of all this, recently, after the last federal election, I'm starting to get it.
Quebec is different than other provinces. The things we care about are different than the general population of North America. We believe in free health care and education for all. Not as a concept, but to the core of our being. It's ironic that we care so much for everyone, but lose sight of it over something as trivial as language. Francophone Quebec is afraid that we're going to lose these differences, this identity by way of dilution of the language. This is where the animosity comes from. It's rooted in fear, not in hatred. The fear of losing the language is justified and real. French is fading and being mixed against the cultural influence of English media. In 50 years, it will be the second language in Quebec.
The fact is, today it's a French province with clear laws that signage and publicity must be in French first, and in English second. This said, the language police are overly aggressive and make silly moves like this pretty often.. and unfortunately it undermines Quebec and the social issues it faces. It makes us seem silly and petty to the rest of the world. If you live here, after things like this you have a harsh taste in your throat once you're done rolling your eyes.
It is getting better. The next generation understands the world better than the previous generation, and things continue to improve.