Why aint more rappers humble?

It's all in the presentation. Rappers have an "image" to maintain and unfortunately, their success thrives off of how real they keep it. But, I also want to point out that Bones Thugs and Harmony have quite a few songs about offing people. That's why I say its all in the presentation. It doesn't sound hard but some of their content is hard, the harmony of their music keeps provides a laid back mode. In your defense, they mostly want to get high and chill, maybe brag about selling drugs.