This is year 1 of Switch, so virtually all first party games are big guns that are undoubtedly meant to sell the hardware. This isn't complemental software by second and third string developers to round out the library.
It's how Nintendo goes about business. Their top teams are the first ones to work on new hardware while lesser studios provide the late life support for an older platform. First party software that costs less than $60 on a more frequent basis is only a matter of time because not all of the studios who worked on 3DS games are going to increase their production values to the same level as Nintendo's most important IPs.