This makes total sense in a way. After Nintendo's last jaunt with the pedophilia scare with swapnote, they have decided to make it so that their system has as little contact with accountability as possible. And the best way to achieve that is to simply remove the ability to communicate online from the console, period.
So then the only way to communicate is to use an external system (which Nintendo is not responsible for), or to use a smartphone (which Nintendo is not responsible for) with their paid app (which, in Japan at least, is a legitimate barrier, think not being able to buy CERO-Z games with PlayStation wallet, only credit cards on PSN)
Also, because Nintendo, your gonna get your friends list from your contacts (all on you, not Nintendo). And if everything does somehow go all Swapnote, they can lock down the app or purge it while leaving the Switch untouched.
Yes this is a flawless theory from yours truly, please understand.