I guess one argument is that you can only play both FE and BOTW on Switch. So if you only have 3DS or Wii U, then you might as well buy Switch so you can play both. And at higher production levels to boot.
It's hard for 1st party dependant consoles (like Nintendo's) to manage transitions by putting compelling games on the new system, but not completely abandoning a large player base on day one of the new system. Esp with a successful product like 3DS there is a certain amount of revenue dependence on the legacy system while the use base of the new system ramps up. Where there is considerable 3rd party engagement with a console, the 1st parties can more easily focus on the new generation because 3rd parties can be relied upon to release cross-gen games, esp including the annual franchises like Fifa, CoD, previously Ass Creed and others. But Nintendo doesn't quite enjoy that same level of 3rd party engagement, particularly with the annual franchises, and so it needs to manage the transition with cross gen games more in-house.
To be sure it's a rod Nintendo made for its own back. But people should not complain now about something that has become embedded in Nintendo's modus operandi over the course of several generations.
“The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt.” - Bertrand Russell
"When the power of love overcomes the love of power, the world will know peace."
Jimi Hendrix
