It affects anyone that lives along a country border so just because you have not seen the issue before, it doesn't mean it's rare.
It would for example affect anyone living along the US/Canada border, US/Mexico, most country borders in Europe, Asia, the Middle East, etc....where it's necessary to force select your mobile carrier.
As an example, it's estimated that 75% of all Canadians live near the US border. Lets knock that down to about 35% (guesstimate) within a US cell mast. Of that 35%, 56% own a smartphone (19.6%), and 33% of those own an iPhone (6.5% of the entire population of Canada are possibly affected by this.
We're talking 2.5 million users on that border alone.
Not what I would call rare.
Obviously much of this is speculative and the numbers will vary but millions will no doubt be affected but a very stupid problem yet as you say, because the developers are not in the same situation, they will probably never fix it because it's never seen as an issue which is my point on your answer.
References:
http://www.ctvnews.ca/sci-tech/goog...-canadians-addicted-to-their-phones-1.1388185
http://www.ctvnews.ca/sci-tech/goog...-canadians-addicted-to-their-phones-1.1388185
https://www.google.co.uk/search?q=population+of+canada
