I don't see why it couldn't. There's already a UVC USB Gadget driver in mainline Linux and the rest is just a matter of beating the video stream into submission using Gstreamer or something similar. But just the BOM alone would cost well over 100€, which can usually get you a used compact camera and one of those dir cheap capture cards everyone is talking about these days and is probably comparable in quality but actually has things like autofocus and a decent zoom range.