Not exactly the Wall Street Journal or NY Times here...this is just some guy on the internet speculating. I wouldn't use this article as your justification for a generalization that "CLT isn't as solid as some think."

CLT is incredibly cheaper than MIA (and almost every other airport in the country as well). CLT's ultra low CPE combined with it's geography give it at least a fighting chance to exist in some sort of hub capacity in a post-merger scenario.

One of AA's biggest weaknesses in their route network is the East Coast, and CLT fills that hole really nicely. I just don't see how you can shift all the capacity that currently goes through CLT to MIA/DFW/ORD. I've been thinking about different route scenarios and what the alternative would be (without flying on another airline) if CLT goes away.

MGM-CHS (had a colleague do this this week). Without CLT, you're going to go MGM-MIA-CHS? That's literally twice the time/distance; If I were looking at those flights, I would switch my business to DL to go through ATL in a heartbeat. What about SAV-BWI? Most people would not fly down to MIA for that; sure, you theoretically could route through DCA or PHL, but those two airports really don't have the capacity to pick up hundreds of flights worth of connecting traffic that's currently handled by CLT. Lots of routes like this: RDU-BNA, CMH-ATL; LEX-TLH; HSV-ORF, I could go on and on.

I just think there's a place for a second hub in the southeast besides ATL, and MIA certainly isn't it.

And again, the landing costs-CLT is literally pennies on the dollar to MIA in this category, and when you're running hundreds of flights a day, that makes a big difference. On the flip side, there is certainly merit to the argument that CLT doesn't have the O&D size to support a hub, but I don't think that's the only factor in play here. Anyway, just my two cents!