There aren't many liberal, leftist, actual-libertarian, or centrist personalities with huge audiences. The only ones that come close to the far right are "dirtbag leftists" like Chapo Trap House who use an equally obnoxious anti-intellectual straw man bashing style. If you want the audience, apparently you gotta troll and get stupid. I get the sense that the people who would make up those audiences for higher-brow content have better things to do.
I noticed a distinct change in his guests and style when he started to get big, which probably means he's feeling the pressure to rake in those ad dollars for the networks.