This "purity" arguments of keeping gaming devices clean makes no sense. If this was the point TVs would be only to watch broadcast shows and mobile only to make calls
The ideia of a multimedia device is good regardless of what the system was mainly designed to do. I'm sure nobody here think it's a bad thing listen to music in smartphones, why would be a bad thing listen music in your Switch?
In reality it's something I would love, plug my phone on my Switch and run Spotify while I play something, currently I need to plug it on my smartphone or PC and keep both devices active to make it work