OK, I'll bite, since no one else will.
A "true dancer"? What can I say that will encompass all the styles from dancesport, to tap, jazz, ballet, modern, and yes, hip-hop?
Here's my take, for what it's worth. To dance is to express yourself physically. It doesn't even always require music. However, I believe that "true dancing" does require an emotive element...the desire to express an inner emotion to your audience or your partner, or even yourself. True dancers can become their own emotion in movement, rather than trying to "create" emotional movement. Now that's a fine line. Usually I think it takes years of study, becoming in touch with your body and developing innate muscle/mind coordination to achieve the spontaneity and release that can be seen in a true dancer. You have to get beyond the choreography, beyond the count, beyond the physical strain...so that you can dance your heart and soul within the frameworks you have built. It takes a lot of practice, practice, practice, but it can be done in any medium...tap, jazz, ballet, modern, dancesport etc...A "true dancer" has mastered his/her body and mind, they are beyond counting, or tiring, or thinking...they are able to just move. Of course, they are on time, and straining, and thinking...but they have so imbedded the actions that they are second nature.
In these dancers you can see the music in motion...feel the emotional expression, and it is a language much more complex than our spoken one.
That stated...you can see glimpses of this in lots of dancers...some people might mention "natural dancers" or people who seem to have a natural ability to let their emotions show through thteir body language...it takes more than that to be a dancer...but a lot of great dancers do start that way
Best of luck to ya. Hip hop is great for anyone's dancing...brings back freedom of movement...shakes up the body memory of anyone used to classical training...gets things stirring...and lets you have total interpretive freedom. I love it.