I don't believe I'm picking Hall's career based on her over-all success, there are certainly women out there with more successful careers. Although she still does pull in occasional championships, a la last weekend. It's more like my perception that she can do whatever, whenever, if she feels like it. Like there's no definite plan, she could show up anywhere. It's as if even though she could be training for the US half-marathon champs, another race could ask her to come and it'd be, "Sure, I'll run that." And not have to bow out because, "There's the half marathon champs in a month and I'm training for that. Gotta focus on training for my half." Do both! So maybe she's reached a level of success and ability at multiple events right to the point of being very good, and desirable for an RD to invite to a race, or be able to qualify for a race, but not being pigeon-holed into that event for specific blocks of time. I'm a marathoner now, no time for a road mile. It's my idea of her having a very fluid situation that appeals to me.
And this is just all guessing, I have no knowledge of her aspirations. Who knows, maybe she's so hell-bent on making an Olympic/World team it drives her nuts.
Maybe she's the elitest hobby-jogger. The hobbiest jogger of all of us.