Right there you have another example of the same thing. You wouldn't call a RS-170A signal a "BNC" signal because BNC's are used for all sorts of signals including composite video and component video (most commercial video equipment uses/used BNC's for composite). And yes I can still remember the red is right etc.
In the case of IEEE-1394 there is a specification by that name that describes not only the connector, but the electrical properties of the cable as well as the format and content of the signals carried in them along with a lot of other technical stuff. While nothing prevents someone from using these same cables and connectors for other purposes, there is a definite tie in by a world recognized standards group between the name, the connector, and the cables.
This is not the case for anything carried on coax cables with RCA phono plugs on the ends. Heck, I've seen devices that were powered through RCA connectors, inputed and/or outputted RF through them, and even sent digital data through them.
The RCA connector is a defacto standard that's been around for a lot longer than composite video signals travelled between consumer A/V devices. AFaIK it was adopted for that purpose simply because it was already in use on the audio only consumer gear.
While not a true reference, these links give a definition of an RCA (AKA Phono) connector:
http://www.audiovideo101.com/dictionary/dictionary.asp?dictionaryid=362&term=RCA_Connector
http://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci786116,00.html
Check any electronics parts catalog and they will probably have multiple listings for RCA jacks and plugs. No mention of composite video is likely included.
http://www.globalsources.com/gsol/I/RCA-connector/p/2000000003844/3000000157652/sm/8802000102.htm
That said, this is getting to be a rather pointless debate. I only jumped in because you incorrectly (IMO) contradicted something in Jesse's post on the subject and I thought I'd set the record straight.
FWIW you have my complete permission
to use the phrase "composite cable" to describe any cable carrying a composite video signal if you so desire.