It amazes me how many people think how unimportant real, signifcant third party support from companies like EA is for long-term success of a console's life.
Yes I know, "Fuck EA, they're cancer, worst company in America"... EA brings in $5 billion a year. That's an enormous consumer base. Their games matter to the gaming community whether you like it or not.
There are millions of people out there that won't consider a console that doesn't have games like Call of Duty, Madden, Grand Theft Auto, and Assassin's Creed. How many Switches could Nintendo sell if they had these franchises on their platform?
Well, exactly one of these IPs is actually from EA, so this is not the greatest of all points. (Also technically AssCreed is on Switch, but you mean current ones.)
But you have to see, that this sword uts both ways: Think how much more Sony and MS could sell, if they had games like Mario Kart, Zelda, Xenoblade, Pokemon and Civilization.
The basic point is: a gaming platforms sells based on the games it has. More games is always better. Some games are very popular and help more. And different games deliver for different tastes. So if current Nintendo platform owner dislike games that aren't actually on their platform it makes a lot of sense: if they would like these games, they had chosen another platform. And that current PS4/XB1 owners dislike Nintendo games makes also sense - if they would like them, they would own a Nintendo platform.
Would it be great if one platform had all games? Pronably that would also be bad, but the more games a platform accumulates, the better. Currently it doesn't look too bad for Switch. That the lineup doesn't contain stuff you like means you probably don't own one. But that doesn't change the fact that millions like the Switch - because they have different tastes than you and therefore deem different games important.