Despite understanding all this and being okay with the product as-is
I'd still have loved the option to sync my VC library with this thing and download other stuff, even if the option is really really hidden and most people will be able to experience this thing as a plug-and-play system.
I agree completely, but sadly we are not the target audience for this.
I'd love for them to release a "NES Classic Pro" or something similar that has Wifi, eShop, the ability to link a Nintendo ID, and had a port to plug in original game cartridges / controllers as well. But every increase in functionality we're asking for is an increase of the cost of the unit itself, meaning less people would buy it. It'd be like making a sub-niche product of a niche product, and I can't imagine it would sell very well outside of hardcore retro-gaming circles.
For now, the truly dedicated fans of the NES will have to stick to WiiU or 3DS (for official VC releases) and emulators, android, raspberry pi, etc as an unofficial means of playing these games.
EDIT: or, you know, original hardware.