Dre won't drop Detox because he's afraid of it being anything less than an undisputed classic. He's never been about the lyrics. It's all about the production. The Chronic isn't considered to be a classic because of the lyrics, it's considered to be a classic because it's one of the best produced hip-hop albums of all time. Dre is a producer first, everything else is secondary. There are so many rappers who have acknowledged that Dre isn't really a rapper, he's just one of the best producers ever. That's why I'm convinced Kendrick Lamar is going to be a force to be reckoned with. He's already spitting fire on everything he touches, so we know the lyrics are there and now with Dre producing, he's going to be unstoppable.
As for Dre being the richest man in hip-hop, I'm surprised but not surprised he's making it off of the beats headphones. Everyone and their mother owns a pair. Honestly, give me a pair of Sennheiser headphones any day over a pair of Beats: they're cheaper and they sound just as good, if not better.