During the Gamecube/GBA era, handhelds were about 80% of the revenue, but the home consoles were about 80% of the expenditure. I think you're right, that during the Gamecube and Wii U eras particularly, Nintendo did feel more like a handheld company. But (and this is me personally), I still considered the N64 to be the main platform during its time, even though GB was booming and bringing Nintendo popularity to new heights - a lot of that was the Pokemon crowd. But that's only my personal feeling about the N64. Objectively speaking, the handheld sector was bigger during the N64 era with few exceptions (mainly the Goldeneye 007 period).
The Wii and DS were a different story, the Wii sold fewer units but likely had a lot more people playing it from the heavy multiplayer focus of the console, they were probably somewhere around 50/50, but the Wii generally felt like the lead platform that generation. With the Wii U, I found it really difficult to find anyone who wanted to play anything on it unless it was Just Dance and copious amounts of alcohol were involved.
I describe myself as a little dose of toxic masculinity.
