Many people make the naive mistake of assuming that this
isn't what people want. The truth is that most people, and especially your average reader who doesn't spend their time on online forums as a matter of routine, are distressed by dissenting opinions on important topics, and will reject platforms that thrust this upon them.
For example, I've posted a number of "controversial" comments on HN that were purely technical and resulted in substantial discussion of the intricacies of the solutions discussed. Because these comments condemn the listless tech-hipsterdom that many devs rely upon to feel valuable (and that many important companies subtly leverage), people complained to the mods, seeking protection of the echo chamber. Apparently some of these people were important enough that HN reacted by throttling my account, initially by claiming my posts were too "tedious" and later revising the rationale to the facially spurious explanation of "engages in flame wars".
I haven't flamed anyone, but now I can't participate much in active discussion threads, hitting a something like a 3-hour throttle at something like 5 comments within an hour. Because my voice was drowning the chorus of echoes a little too much for comfort, and this displeased people whose opinion HN values.
This craving for echoes of validation is why reddit can't shed its negative image. reddit's concept of a unified identity with "default subreddits" severely limits the site's appeal, because anyone whom doesn't find the front page appealing is going to leave. Since the front page frequently contains acerbic content that is either critical of a large section of the public or presented in a manner that is conventionally considered crude, hostile, or defamatory, many leave not only uninterested but actively offended. How would your mom react if she loaded up reddit.com and looked around?
This is why the big players like Facebook and Twitter start each user with a blank feed and suggest only the most generic initial follows (usually late-night talk hosts, reality TV stars, and sports figures), and proceed to give each user total control over what they see. People demand echo chambers.
It surprises me to see jedberg still confused about this after all these years.