Okay; it's true that it would be more jarring if an interviewer had a similarly bad habit, and that people who work in broadcasting are rightly held to higher standards.
But I'm not sure just labeling it a filler really gets to the root of the issue, because the problem doesn't seem to be only that the interviewee is at a loss for a better word or trying to think what to say. The fact that many of them seem to be young academics or researchers, people who are fairly well educated and clearly used to explaining things, doesn't seem irrelevant. As a demographic, the group isn't otherwise at a loss for words; they don't speak haltingly or stumble over the right word in other instances, and the rest of their speech isn't punctuated with 'uh' and 'um,' as might be the case with people who are less accustomed to speaking in public at all (like, say, me). Indeed, many of them even come across as glib, relatively fast-spoken. They just happen to use this word when they answer a question.
That's why to me it makes more sense to call it a tic, a bad habit, something that they've picked up in a particular social milieu without noticing it. I just can't understand how they can have failed to come into contact with anyone outside that group who could call them on it, make them aware how annoying it is.
But I also can't understand all the people who now say 'July one' instead of 'July first,' or 'nucular' instead of 'nuclear,' or whatever. I think they must be people who just like to use the speech patterns of an in group, who feel comfortable fitting in, repeating what they hear around them, but who don't particularly think about language for its own sake. It just concerns me to think that that unconcern seems to be creeping into the academic world, including people in humanities disciplines who you would hope might be more attuned to language.