It's completely true, but the article only considers trains. Some countries ignored their train infrastructure, somewhere it's hard or expensive to build it and

It's completely true, but the article only considers trains. Some countries ignored their train infrastructure, somewhere it's hard or expensive to build it and Montenegro is both poor and mountainous, making it hard and expensive to do. On the other hand, Montenegrins are well covered by cheap flights and most of the population is within driving distance to an international airport.