The other way is that downvotes are a great tool for ensuring high quality discussion, and if the thread is about podcast episodes, then downvoting full podcasts helps keep the thread organized. Downvotes aren't necessarily bad, they may just mean - hey, this doesn't belong as much in this thread, so I'm voting on it to help organize the thread for other readers.
"What's your favorite podcast" is a vastly less interesting and different question to answer. Impactful episodes can even appear in podcasts you generally dislike or don't agree with.
But I would say that failing to describe a podcast and why you like it (or specific episodes) is poor communication. It would be like a thread about food and someone saying, "Italian cuisine is great. It's delicious." I know nothing from that type of comment about what makes Italian cuisine distinctive and what attributes stand out for the commenter. There are a number of comments like that in this thread.
EDIT: downvotes probably aren't available to you yet, NilsIRL, I think the karma threshold is higher (500?).
To be fair, though, the flag button is hidden. You have to click on the comment time stamp to find it. Some people seem unaware of this. It appears to be a minor source of confusion around here.