I use AC 6-7 times per year between Montreal and Frankfurt, and have to agree with your take on the service and general lack of concern from the FAs. I think most of us are very understanding that people can have "bad days", but I can't believe they can have them as frequently as I have witnessed on this route. I have also heard open conversation which included whining and clearly negative comments. I know that these issues are apparent to some degree in almost every company, but can only take this open complaining as a very serious lack of professionalism.
I also think it is is a sign of a very serious morale problem. This business of the "merged" crews from former Canadian Airlines with Air Canada has never really been a popular on amongst FAs, and the former Canadian people like to wear their logos upside down as a form of showing their allegiance to their former company.
Comparison to other airlines is not easy, but honestly I have found that Air Canada has not kept up with the times with many things. On the Air France A330, every economy seat has a personal screen, and a controller that lets you choose your movie or games to play. Even in economy they come around before meal service, and drop a card with the menu choices. I found them to be very accomodating, no problem to ask for something, since they were already making repeated rounds with extra rolls, and of course wine. On my last trip to Frankfurt on AC, I was upgrade to Business, and while I was very grateful for the legroom, the food was nothing special, the seats are large but outdated and in poor condition. Again, the service was also very lacklustre. I have also recently travelled on Lufthansa, BA, and KLM, and would have to say that Air Canada's service standard is the lowest, matched only by KLM. It wasn't like this 6-7 years ago.
Having said these things, I feel it is only fair to mention that on occasion I have seen absolutely wonderful service, and a couple of medical emergencies that were handled very well, and the concern for the passenger was clearly very genuine.