The market is fickle. AA introduced 'extra space' a few years ago and promptly returned to sardine seating. if the market wont pay a premium for the extra leg space, there is no incentive for the airlines to do it. for all the whining, people will still use online engines and pick the airline whose fares are $10 less than others.
AC is better than the other NA airlines. Browse the other forums in this place and you'll find most of the threads are complaints. EK, CX, SQ, BR all.