Ah, so now there are tactical and gameplay reasons to voice chat? What about the countless posts saying that voice chat is not that essential for this game? Anyway, the point is countered by the fact that online games with voice chat allow to manually mute the people you don't like. Or have the option to just voice chat with team mates or just people on friends lists, etc.
Related to the above and talking about potential "disadvanatages", Nintendo is supporting the option play with no motion assist, yet this could also have gameplay impact. But the option to turn it off is there.
Your second point, far more complex online games, with more people playing at any given time and more critical of twitch response do support voice chat.
It boils down to:
1) Part of user base don't like voice chat. i say Bravo for diversity.
2) Other significant part wants voice chat. i say Bravo too.
You don't get voice chat, you alienate part of that user base. You put voice chat no one loses functionality since the part that don't like it turn it off.
Awaiting your response.