I think the problem is in the opposite direction. Society is too ideologically homogeneous in being against socialism. The major narratives are controlled by nation-states and corporations, social media are infested with political advertisement and propaganda.
So, as others say, I believe it is sorta uninformed and middle-of-the-road fallacy to find a corner of the internet where you can speak your mind without being harassed by white supremacist trolls, and say we need more diverse views.
Right wingers have (had) Parlel, Gap, TruthSocial, now they have X, and Facebook, where they were also dominating and harassing in the past. No leftists and/or genderqueer person would survive a day at these platforms.
But Lemmy being primarily/explicitly leftist is the problem, and you suddenly are alarmed for echo chambers. This is not quite fair, now is it.
As for Lemmy per se, I don’t think it is too homogeneous. I debate centrists and liberals every other day. And recent discussions showed that the amount of latent transphobia in the site is shocking, with people knowing next to nothing apart from 4chan/MAGA talking points.
How can this happen after all these years of activism and outreach. It is because of the ecosystem of echo chambers in the broader communications and media landscape. This discourse never reached those people.
Considering it was the position of major medical and professional organizations, it shows that the pathology lies with the existing social media and broader media enterprizes, with a prominently selective messaging.
Do I need to say that this led to widespread science-denialism for which mainstream platforms are clearly to blame?
If your inquiry is honest, then the only explanation is that the propaganda apparatus works so well, that the (relative) absence of the dominating narratives makes you anxious that you entered an echo chamber, when in fact you probably have been in an echo chamber so far.
This is not an universal truth.
Nazism is explicitly deemed unworthy of respect in some legal systems, like Germany or the UK. MAGAs, white supremacists, and alt-righters are objectively too close to nazism, therefore their opinions are unworthy of respect to start with.
There is also the paradox of intolerance. If you let these people in, to respect their opinion, they will take over and deprive people of the right to live. They don’t play by tolerant society’s rules, so they they don’t get tolerated.
Here is the opinion of the scientific consensus on transgender people, which is have been so for years, if not decades.
We have been harassed, bullied, doxxed, and banned for bringing those up in all major social media platforms. TERFs, white supremacists, misogynists, racists, have always gotten away in these platforms with punching down on leftists, African and Caribbean reparations activists, feminists, and queer people. They were protected by equally bigoted moderators under the guise of entitlement to their opinion, at the same time that all these other opinions are bashed and framed as “overstepping”.
This is in line with what the EFF and Techdirt, which are both vocal First Amendment absolutists, have already said that what X and Facebook do now is in fact amplifying hate speech and effectively suppressing the free speech of gender and sexual minorities.
And this has been the situation for years, take for example the online harassment of feminists .
It is a deeply systemic bias, due to centrist indoctrination in broader society, that it is the leftist and inclusive spaces that are called out for lack of diversity for responding to harassment and bigotry, when the voices and lives of people are simply dominated and evacuated in major platforms without an iota of moderation and responsiveness to punch-down harassment.
Let alone that in the light of the most recent developments, which consolidates the above tendencies, makes the timing of the tolerance argument even more ironic and dishonest.