I didn't see the talkshows today but I can understand the point you're making here.
--Messaging is useful when it helps the subject matter expert (SME) put their response in context rather than having the interviewer create the context for them. SMEs need to have that power because otherwise they are at the mercy of everyone else's agenda, axe to grind, point of view, ideology, etc.
--Messaging is not useful when it is used to distort or suppress the truth or to propagandize. Not only don't those techniques work, but they have the opposite effect of destroying the speaker's credibility (as you point out.)
--Over the past 10-15 years or so, coinciding with the rise of branding as a "mass" tool (meaning that everyone "gets" it and uses it for their own gain) -- we have seen the rise of phony marketing speak as a substitute for actual substantive responses to questions. Like you, I find it completely frustrating to watch a TV interview and feel that the speaker is somehow trying to hide, evade, manipulate, project an image, etc.
The solution to all this is not to throw out the baby with the bathwater. Dense jargon, words with no framing or anchor or context, and simple avoidance would be the result. Rather communicators really have to up their game and understand that the audience to whom they speak is every bit as smart as them, maybe smarter.