It ain't like that.
It's not easy to make something with mass appeal. But it's also not easy to make something that intellectually matters. These are difficult things. Becoming a career rapper is not easy (unless you have friends in high places who carry your ass; right, Cappadonna?).
So when Wiz Khalifa drops his next banger and you think to yourself, "I could write something way better than that," you're looking at it wrong. You (assumingly) don't have the charisma to pull off what Wiz Khalifa is doing. You don't have the swagger or the understanding of what's going to work.
It's the same shit across all genres. Max Martin, the guy who wrote a lot of the biggest boy band songs of the late 1990s (Backstreet Boys, *NSYNC, Britney Spears, etc.), is a fucking genius for his dynamic understanding of the mainstream market. But his songs on paper read like they were written in crayon by a 12-year-old girl. That's kind of the point. No one did it better than him at the time, in that genre.
Now, in order to make music that permeates pop culture in such a way that it has real staying power, you have to find a balance. Jay Z did that better than anyone ever. That's why he gets that title as the best ever, because he reached almost everyone who would ever listen to rap (and some people who wouldn't) and made music that can stand on its skill ("Meet the Parents," "D'Evils," "Public Service Announcement," etc.) and music that just bangs for the common folk ("Empire State of Mind," "Big Pimpin'," "99 Problems," etc.). And on top of that, unlike Notorious B.I.G. or 2Pac (though it's easy to say they would have, there's no real proof), he did it for years. That is not an easy thing to do.