You start by allowing "politics as a broader thing", flash forward a year, then you notice that at any given time, at least 20% of the frontpage is occupied by people screeching their throats raw with some incendiary hyper-partisan rhetoric.
The failure mode is rather obvious, and also extremely hard to avoid in practice.
"If putting rat poison in the burgers would cause people to die, what does this say about the quality of the burgers?"
Very little.
I've been told most hackers are humans - not machines or some kind of alien species. So I fully expect hackers to have the flaws people tend to do.
Partisan politics have a nasty habit of capitalizing on human flaws, and bringing out the worst in people who engage deeply in them. Which, in online communities, can have a self-reinforcing effect.
And yet we are talking about partisan politics. Because it's the lowest common denominator of politics. Because it's the failure mode.
You can say "not all politics are actively toxic to human minds" and point at 18th century philosophical works all day long, but we both know that 18th century philosophical works were never the concern.
You are persistently referring to partisan politics in your comments. I am not.
I have repeatedly distanced myself from partisan politics in this discussion. I believe I have not made a single statement supporting partisan politics, much less a particular party, in this entire discussion. If you disagree, perhaps you can quote an example.
The failure mode is rather obvious, and also extremely hard to avoid in practice.