I simply disagree. You are saying that if there were no Tupac, all the negativity in the Black community we have associated to Gangster rap would not have existed. Tupac was a solid rap artist, but there are a great many solid rap artists.
Now if you say that if gangster rap did not exist at all there would be less dysfunction for the generation of Black youth were reared on this stuff. I'd be willing to say perhaps. But then you'd also have to explain why white boys who buy most of the gangster rap were not, apparently, similarly effected and why many Black men are not.