Because there’s so little cross pollination today everyone lives in a bubble. If your Facebook is full of right-wing stuff, you only watch Fox News and only listen to Larry Elder, you’ve got an echo chamber, breeding ground for radicalization.
Having a wide variety of guests actually fights that. You listen to Bernie Sanders, then Alex Jones, then Ben Shapiro, then Edward Snowden. Rogan breaks the echo chamber. People who might only listen to Alex Jones have a chance at listening to Bernie.
Why? Why do I suddenly need to know everyone's take about everything? Why is it important that we know what our favourite actor thinks about Trump?
Everything is publicity. It's not achieving some important social need, its driving people towards new products. Interviewing Alex Jones isn't doing anything except making more people know what an Alex Jones is.
Is that why the kardashians are so famous, because their continued media presence is our opportunity to see if they make sense? No, they are just crap and giving them more sunlight just gives them more undue fame, money, and power.