well if you don't like rap in general, I can see why you don't like 2pac. his music is the very essence of what rap is supposed to be.
However he was a very versatile artist that made many positive and uplifting tracks, such as Changes, Heaven Ain't Hard 2 Find, and Dear Mama.
...and lastly, many rappers come from neighborhoods filled with crime, poverty and hopelessness. When they make music that comes off as negative, they are expressing the anguish they feel from living in a country that has a history of oppressing people of color. Its really just them talking about the things they go through or the things the see other people go through. I think its kind of important that they shed light on the things that happen in Inner City America. We can't fix problems until we know they exist.