Of the sources noted that offer 24/7/365 news and information reporting and that is offered globally, AFAIK, the choices are CNN and the BBC, "maaybe" Reuters too, but I'm not aware of Reuters offering a global (or even U.S.-only) cable TV offering even though it does produce video news content. I don't know for sure, but I'd imagine that airports choose CNN over the BBC, especially in the U.S., because the majority of airline travelers are American. That said,
one doesn't have to consume the airport offered CNN programming. Many U.S. airports offer Clear Channel; indeed all of the major U.S. airports I've been to do.
As go the major cable news organizations, they all do a fine job on news reporting. Where they differ is in (1) the nature of commentary and analysis they offer and (2) the extent to which their programming is comprised of news, analysis (neutral) and commentary (conclusions based on analysis -- biased) . CNN (in the U.S.) offers slightly less overall commentary than do Fox and MSNBC [1], so that may also have something to do with CNN's being dominant in the U.S. airport television space.
Outside the U.S., CNN (which is branded as CNN International and has a completely different programming lineup and format) is nearly all (~90%) news and professional expert (not professional pundit) analysis....that is to say, it's who, what, when, where, how, and rational explications of why if enough is understood/known to make any such remarks. CNN International also spends a fair amount of time having experts share analysis,
i.e., whatever be the rationally sound/cogent implications, constraints, and so on of the "who, what, when, etc." and various prioritizations of the "who, what, when, etc."
Simply put, CNN International's broadcasts and content are what allow CNN to assert that it's "the most trusted name in news." About 325M people in the U.S. see CNN. The remainder of the world's ~8 billion people see CNN International.
Why the difference in content? I suspect the answer is Fox's presence in the U.S. Fox introduced the "cable news as entertainment" model whereby cable news content is structured to attract a predictable demographic that advertisers can in turn rely upon and, as appropriate to the product being promoted, develop advertising messages or place advertising messages so as to maximize their returns from having bought advertising time on Fox. The "cable news as entertainment" model, in keeping with the general paradigm for entertainment, doesn't challenge viewers' preconceived notions about anything material.
At the time of implementing that model, Fox's execs, recognizing that the U.S. already has more than enough people who self-identify as conservative, made a deliberate choice to tell conservative viewers what they were already inclined to accept. The strategy wasn't to skew the news; the strategy was attract reliable quantities of viewers so as to, in turn, attract ad revenue away from other networks. The tactic for realizing the strategy is delivering messages that people, in one way or another enjoy receiving. Hence, news as entertainment.
Remember, ever since news production and delivery became something that had to happen in a financially solvent and enduring way in a competitive marketplace, cable news organizations had to become not "merely profitable," but rather "competitively profitable."
What's the difference? In a "merely profitable" environment, a firm's ad prices increase as the cost of producing and delivering content increases. In a competitively profitable" environment, when a competitor develops a "hook," a differentiating factor, that attracts customers, competing firms must at least match the "hook" if they are to remain in business, remain competitive. In both environments, a firm's ad prices depend also on viewership quantities and demographics.
Fox's "hook" to make news become in some measure entertaining was commentary, namely delivering tons of it as opposed to tons of news and analysis. That it worked should surprise nobody: news is what it is -- the body of information any given network can present is the same, and one can get it from the over-the-air networks. What those networks cannot deliver is tons of commentary and they're not going to change that because they have "conventional" entertainment programming -- sitcoms, dramas, game shows, etc. -- to attract viewers to their networks. A cable news network, on the other hand, has to attract viewers to one general category of content, news and information. It stands to reason than that if the news is entertaining in some way, more viewers will tune in than were the network to deliver "dry" news.
Recognizing that modern cable news offerings all have some measure of entertainment bent to them, which for news is the commentary portion of a network's program offerings, airports basically have five choices:
Were I managing the commercial portion of a U.S. airport, I'd go with CNN or Clear Channel or both, mainly because I know that the people patronizing the airport are typically only there for a brief time and want to be brought up to speed on whatever they can before boarding a plane. Were I running the general aviation section of an airport, I'd do the same thing that's done in many general aviation lounges: put the remote control there and let passengers deal with it on their own. [2]