I dont think that´s the case. Looking back at sales of third party games on Wii, DS and 3ds, there are some titles that sold very well, although we may argue most of them were exclusive of those platforms.
There are even a few but very curious cases of titles that sold equal or better on Nintendo platforms than others, like Rayman Legends and Sonic All-Star Racing Transformed.
I believe that it may feel that third party games are selling better on the Switch because the system is getting the attention of may consumers who are not "die-hard" Nintendo fans and are interested in playing more than just Nintendo games.








