Okay.
a) Switch is a hybrid--different styles of play united in same console to appeal to disparate audiences.
b) This comes at the cost of making it a luxury handheld and a weak home console.
c) It comes with the potential benefit of games originally for one audience filling in the gaps between games for the other audience and also pulling one sort of user to further Nintendo product.
Now let's toss out c) and only support the Switch as we would a home console. Let's just replace the Wii U. Moreover, let's replace 3DS with another, incompatible device.
d) Switch now cannot leverage the unique software traditionally Nintendo handhelds receive to make it more compelling as a console in the west.
e) It also will fail to get the games that drive Nintendo handhelds in Japan. It will compete and lose against Nintendo itself in Japan.
You likely end up with a failure on the level of Wii U when you could've had a platform approaching N64/SNES/3DS level of success and you keep yourself in the problem of disparate devices for disparate audiences that you can no longer support.