The OP uses the word "insane", not outlier. It's clickbaity, and used in jest, but I think it better captures a subtlety of this phenomenon: The prolific commenters are molding every discussion in their image. They might have an interesting angle on the story, or they might just be saying trivial things with beautiful prose. In any case, there is a lack of diversity in general -- discussions are driven by the worldview of a few.
That would be an argument for lurkers to make an effort, even if, like this comment, it's just a barely-formed idea.
Edit: "molding the discussion" -> "molding every discussion"
In other words, we only hear and watch stories from those people who chose storytelling as their career, and if you assume we are inevitably influenced by their views then we're effectively taking advice from them. This means entertainment shapes the viewer-listener's interpretation of reality to better fit the model of reality to which storytellers subscribe, but I'm pretty sure that's not a desirable outcome in the long run.
In a recent interview, Michelle Obama said we only ever tell young people about the good parts of marriage. We hardly ever explain to them that it has its ups and downs, that it isn't "broken" if suddenly the lust isn't there like it was in the beginning. She presented the argument in a much more cogent manner, but in any case, if you believe her to be right, then this seems like a specific (important!) example of this broader trend.
There are countless others out there who go on to live perfectly happy lives with perhaps much more useful advice to us, and who would arguably be a better influence overall – you just don't hear about them.
https://www.washingtonpost.com/news/wonk/wp/2015/12/03/weve-...
We have some of the sexyist media around telling us we should all be sleeping around and yet apparently sex is down too.
https://www.theatlantic.com/magazine/archive/2018/12/the-sex...
Are we sure it's any different for other topics?
Also, as for media and marriage I feel like more media is about bad marriages than good ones. A common theme might be falling in love and getting married but a movie about people already married seems rarely about things going well. Or maybe I just have a selective memory.
There are lot of confounding variables, though. Sex could be down because both men and women have to join the workforce, people live with {their parents for longer, with roommates} because rent is expensive, technology lets parents keep tabs on kids better, etc.
EDIT (to reflect your edit, I believe):
> Also, as for media and marriage I feel like more media is about bad marriages than good ones.
I think that's exactly her point. We only ever talk about "falling in love" and "break up". How many songs can you think of that talk about a resilient relationship? Better yet, how many songs can you think of that talk about a relationship in the past tense and say it was great?
I was thinking about this yesterday. An interesting project would be to filter every top 100 song in the past century for love songs, then look at how many stories are predominantly in the past vs. future tense, and then how many of those say good vs. bad things about the other person in the relationship. My hypothesis is there's most forward-looking of those songs talk about the wonders of love, and the past-looking songs talk about how shitty the relationship was and how they're glad it's over.
Extra credits for whoever buckets the data by decade to see if the trend has shifted.