They do talk to conservatives a lot though. Many recent episodes interviewed Trump voters and sent reporters to Republican rallies to hear those "good points" from the source...
But they're still far from actually balanced. As a frequent listener, I'd characterize their overall coverage of conservatives as "a bemused, curious foreign tourist".
Mostly because the people who would be able to do that have "chosen" to retire.
Partisans would much rather that they only hear about the ugly parts of the opposition, and never hear about the ugly parts of their own tribe.