Not sure if this is really worth of a response, I suspect we have a one and done poster here. But, a few things:
- Flying over 7,000 miles in Y with a child is almost never a positive experience, on any airline.
- Every airline on this site has many of these rants. So while AA might not compare well to elite Asian carriers, all airlines upset people every day.
- Many of the problems you listed are not in AA's control. All airlines cancel flights, reroute people, lose bags, etc.
- For your route, the only non-US airline who could do a 1-stop itinerary is China Eastern (PVG-JFK-CLT(onDL). MU does not exactly have the same reputation as SQ, CX, etc.
- Think hard about how much more you will actually be willing to spend next time for an airline you think is better. If CO/DL/CX etc. is $500 more, will you spend $1,000 because you think the flight will be better? With most flyers, the answer is no. Thus, AA does not have a reason to invest in their Y service.
(I saw a post recently recommending a waiting period for new members before they can post. I think this would be a great way to reduce these one and done rant posters.)