Mary Cain should have done the interview. Period. But it's not surprising she refused.
Regardless of whether LRC is the running community's equivalent of The New York Times or the National Inquirer (it's somewhere in between), she is an adult, a professional athlete, and bears a basic level of responsibility to the fan base of her sport. If LRC asked her a question she didn't want to answer, she would have been free to shift the direction of the question, change the subject completely, or simply decline to answer. She's more than capable of doing any of those. Professional athletes do all three all the time. So do professional coaches.
But despite her move east, she's still on Nike's payroll and still under Alberto's thumb. And they aren't too happy with LRC these days.
It's wrong, it's a shame, and it doesn't reflect well on a talented young athlete who also used to be a compelling personality.