I've heard something similar proposed several times, for example Airbus Patent Shows Modular, Removable Aircraft Cabins, and the same issues are discussed every time.
The primary driving factor in the design of passenger aircraft in recent decades has been getting the cost per passenger down, so a solution against which can be said "the whole obsolete airport and airline infrastructure must be rebuilt" has pretty much zero chance of happening, since that would be somewhat expensive.
As far as the safety aspect, the idea of having a detachable passenger compartment that can separately parachute-land in the event of a disaster is also not new, and the obvious issues mentioned in that article seem to apply here also. Big increase in cost to achieve a questionable and at best marginal overall safety improvement in what is already the safest for of transport is just dumb.
Don't get me wrong, I'm glad to see people working on this kind of thing, and I don't want to be that guy that dismisses every futuristic conceptbecause of a few practical obstacles, but I do wish tech journalists would present such things in a more realistic way. Lines like "... and his team are preparing to build a small-scale Clip-Air prototype. They have already initiated some contacts with the aerospace industry" tries to make it sound like this is something on the path to possibly being implemented, whereas the reality is "contacts with the aerospace industry" might not mean much at all.