Social media? Take a look at the bigger picture. When all of those guys started bubbling Blockbuster still existed, cable TV was the main source for television, most people still bought CDs, etc etc. Sources of entertainment weren't anywhere near as diverse as it is now.
I keep saying with how social media has changed it might be damn near impossible to break through, not to mention major labels aren’t in studying in hip hop. Pop, Latin, and County are looking like they will have their time to dominate the mainstream.