In part of that is I dont think AA was ready to share the "Love" with AS having a satellite operation up the road from DFW.
I don't think AA is or was all that concerned about AS's two-gate operation at DAL; it's hard to imagine those two gates making the entire partnership no longer worthwhile. In fact, I'm quite sure that AA is much happier for AS to have a small outstation there than Southwest further boosting their formidable operation there. (Even with AS/VX flights from DAL to DCA and LGA, which were so unthreatening that AS has since abandoned them.) I also suspect that AA is happier to have a partner with those two gates than a bigger competitor (DL or UA). I think that AA's real concern about AS is on the California-based network, particularly the transcons. AS doesn't compete in the lie-flat J/F segment, but they are now a direct competitor on many transcons from LAX as well as SFO-JFK. It's there that VX brought a lot of direct AA competition to AS's network.
Sure AS flies to just about every major city now so partners arent as important as they were in 1994 when we relied heavy on AA DL NW and CO for connecting flights. The loop hole or future problem for AS with dwindling partner ships is regional jet feeder traffic once you go east of the Rockies. For AS to continue to grow at some point theyre going to need a regional QX or contract hub some where for RJ service. Some where like MKE or somewhere where theres room for gates and airport growth. Otherwise without many options to get to smaller airports people are just going to have to book DL or AA or UA even departing from an AS hub to get to where they want to go
There has certainly been a ton of talk in this forum about AS's purported need to have an east of the Rockies hub, in most formulations in some city like MKE or STL that has little enough local traffic that all the other hubs there have failed.
And you say that AS flies to just about every major city now. But I certainly feel the limitations of their network; they have dots on the map for most of the major cities, but I find that AS's network can't actually get me there in less than 24 hours in most cases. As a YLW/YYF-based traveler, it's pushed me over to WestJet and Air Canada because AS's YLW-SEA flights don't actually connect to the east-of-the-Rockies part of the network.