I think the problem here is that any definition for RPG asides from a simple dissection of the acronym (I know RPG isn't an acronym, I just can't think of the right word for it and everyone will get what I'm saying anyway) is going to say "My definition of RPG is:"
It has become an opinion at this point. Despite what you might think from the name, RPGs just aren't RPGs anymore for some people if it doesn't contain high customization of stats, random encounters and a turn based battle system.
The more RPGs come to resembling just Roleplaying a good character (and being more action game than RPG), the more people realize that all games are sort of RPGs anyway, so Roleplaying game as a definition is useless.
It has become an opinion at this point. Despite what you might think from the name, RPGs just aren't RPGs anymore for some people if it doesn't contain high customization of stats, random encounters and a turn based battle system.
The more RPGs come to resembling just Roleplaying a good character (and being more action game than RPG), the more people realize that all games are sort of RPGs anyway, so Roleplaying game as a definition is useless.