It's not a PC in the sense that "PC" is synechdoche for "Windows-based x86 computer" but I think it's important to consider how the overall history of "computer gaming" encompasses these platforms (Apple II, C64, Amiga, etc.) That's the distinction I would draw.
Well I largely feel the same way, but when you get that abstract things start to really blur, to the point where making a distinction between "console" and "pc" becomes meaningless to me. As an example - the MSX. Is it a console, or a PC? Its got a keyboard, it runs basic, but it uses cartridges and has a evolutionary base that the Sega Master system and colecovision share.
Granted, I think the distinction is even less clear today. I really don't see a point in distinugishing between the PS4 and Xbox One and windows PC and Linux PC and Mac today.