score:4
It would seem to depend on exactly what type of "airport chapel" you run across as there happen to be a few different types: http://www.pewresearch.org/fact-tank/2015/07/06/most-of-the-busiest-u-s-airports-have-dedicated-chapels/
If it is as you referenced more of an interfaith space, I would say absolutely.
There do also seem to be some more dedicated areas at different hubs. For instance it would not be so appropriate to get Kindle cozy at the Catholic Mass or Jewish or Muslim prayer services.
You should not be concerned regarding not meditating. Especially in the interfaith chapels, I would expect you to encounter all sorts of people and sometimes no one at all. There could easily be a family taking communion, or young people worshiping, people may gather to mourn, or even just to get away from screaming airport kids. There's really no telling.
I would assume they're a lot like the chapels in hospitals, just not quite as somber.