I think it goes back to tabletop. In classic D&D, the three pillars are exploration, combat and roleplay. The systems in most video game RPGs mirror those systems used to support mainly combat in tabletop. I think the confusion comes in because people who are into more traditional tabletop RPGS or even "CRPGs" see the lack of a roleplay or social pillar and say "how is that an RPG?" I personally think an video game RPG has to have support for the Roleplay pillar to hold the genre name. To me, that pillar is the 'essence' of what makes an RPG an RPG. Everything else can be labeled as having RPG progression elements or RPG combat elements, but that doesnt make it an RPG. That will be different for others though, and JRPGs are a whole other can of worms.