Actually, Brewbuck's original statement was that C++ is superior to C. This argument can, in theory (and most likely in practice), be qualitatively demonstrated. However, I don't think this necessarily translates to C++ being "better" than C - because "better" is a more subjective quality and not easily demonstrable.
Also, I'm not disagreeing with the OP (nor am I agreeing), but I find it surprising that those who do agree have yet to provide the criteria they are using to support their positions (other than, "At the very least, C++ can do what C does").
Personally, I'm here to participate in a discussion and learn, not defend a particular point of view. Describing what one thinks is not nearly as informative as to why they think it.