Chat is a function served by many, many applications and devices, of course, but it doesn't seem strange for games and system makers to provide dedicated in-game/system chat even in the face of Discord. Granted, chat is much more integral to a game than Netflix or even a web browser. But the argument isn't that the Switch "competes" on these facets, but that it's natural to use these apps before/during/after a game session. For example, after playing a game on my PS4 or Wii U, instead of switching off my system to turn on Netflix on my Smart TV, I'll just use the app on the system, because it's usually fewer steps. Admittedly, I rarely use my console browser...but that's because I usually have access to my laptop in my living room. But the Switch is meant to be a mobile device; it's not hard to imagine the situation of checking the web to look up a tip or guide while gaming. Could you pull out your phone? Sure, but again, you could argue this for any function on any system ("just use X device, which most people carry around all the time").
Again, it's not the absence of these things that are alone disconcerting. It's just that we know of these downsides -- on top of a whole bunch of other online-related things that on launch week we have no clue: Nintendo's online account system, social network, purchase transfers, etc., things that Nintendo's history has not inspired confidence about.