I think it's unfortunate when people stop talking about the issues. You're right, people may have made up their minds, but the debate process is not just practice for the candidates, it's also practice for the public to get to know the issues the country is facing.
Of course, it's always up to you what you want to ignore.
1. Propaganda works really really well. Repetiton of propaganda, being a form of intellectual violence, will get people to believe almost anything. Thus, people who control the channels of repetitive messages delivered to the masses control what people believe.
2. The truth is out there, but due to the Dunning-Kruger effect, people who know the least think they know the most and they focus their energy on the most trivial issues due to bikeshedding. Thus, unless carefully vetted, discussion participants will overwhelmingly be people conditioned by repetition, think they're experts and be drawn to triviality.
In order to side step the nut house, just let people believe whatever they want to believe and charge big bucks for delivering messages, especially repetitivly, that do not easily fit in to the ruts in their cognitive road. That's because each time this is done, a small amount of cognitive violence is occurring to your viewers. Most people aren't intellectual masochists so it will drive them away eventually if done too much.
I love the way you put it; this goes straight into my quotes file.
> Keeping ideas that have already become signals quarantined, and minimizing overlap between groups in a context where they are likely to "go tribal" and convert more ideas into signals seems vitally important to me.
In a way, it's what some people do without realizing the idea. It's obvious that once a topic becomes a political issue, the general population loses the ability to discuss it in any reasonable way, so it's best to ignore that topic altogether until at least it falls off the news cycle. But maybe we need a more social-wide tools to "cordon off" topics that were exposed to the disease politics is.