Of course it is predatory. All business is, to one extent or another.
Whether you agree with it or depends (in large measure) on whose axe you are grinding. If you are an AA employee, an employee of an AA contractor, or one of the class of people for whom less competition for AA (this applies, of course, to any carrier, AA's simply our example here), you think AA's policies in this regard are marvelous.
If you are one of the hapless consumers whose pockets are regularly picked and whose choices are restricted as a result of a fortress carrier running a smaller and less-costly carrier out of a particular market pair, well, you don't much like predatory pricing.
AA's consistent pattern of similar behavior has been discussed to death on these forums, and I'll not presume to rehash it now. AA has successfully defended its practices in court in the past, so (at least as of now) "predatory" is not analogous to "illegal."
But there is a vast universe of things one can do which are not illegal (or at which one might not be caught); but these things are not thus rendered fair or right.
...three miles from BRONS, clear for the ILS one five approach...