I often fly the route you describe. And at least there is a daily service to JFK from ORD/DFW so you usually are able to make it. But yes, it requires some extra time as there isn't much choice. IIRC there used to be more flights but they are all gone.
AA also has some longer routes from LGA this year going to Santa Ana for example.
Those AA flights to JFK are partly designed for people to make connections at JFK and not really with a xONEx in mind. And not many people at DFW/ORD need to make a connection at JFK.