Just about all your AA perks are valid on BA as well (except for upgrading discount fares and being unable to pick Y+ seats since BA doesn't have Y+) , so I don't know what you're complaining about.

If you booked through AA.com it is very clear that it's a codeshare flight and not at all deceptive. If you booked by any other means, it's not AA's fault, but the fault of whatever other service you used. In my experience, those are fairly clear as well, though. I could only qualify it as deceptive, if you called AA to book and the agent failed to tell you it was a codeshare.