I disagree with you on 4): there are quite a few insightful interesting discussions on HN about politics I've observed and been part of. They have changed my mind and made me think about things. I find political comments on HN to be noticeably higher quality than other sites, though I'll grant political HN comments are lower quality than technical HN comments.

But the main point I'd like to bring up is this: what you're saying is true about politics in general. But there are a lot of politics which are explicitly about technology and more specifically software technology. Political decisions are being made and laws are being passed that effect our industry, livelihoods, and lives and the community as a whole is infected with this head-in-sand "I'm above politics, politics isn't truly 'geeky' so I don't deal with it, I check out when people describe their emotions or lives instead of technical runtime analysis" attitude. I've observed it online in forums, in industry, in academia, it is an unfortunate facet of the cultural place the tech community inhabits.

But if all of the technical experts eschew politics then these political decisions that seriously effect our lives and our work will still be made: but without our input. By refusing to discuss and create politically active technical communities we cede all power to people who know nothing and care even less about the important technical issues of our time.

The tech community is pretty wide ranging in its political beliefs, but when we discuss the politics of technology there is general consensus on many issues among most: NN is good, banning encryption is bad, unrestricted access to the Internet is of fundamental importance and a liberating force, it would be better to have a choice of ISP, software patents are too broad, copyright/IP law is too extreme and stifles creativity, mass surveillance is troubling (whether you think it is also necessary or not).

There are a variety of extremely political issues that are fundamental to tech:

1) Should developers have a professional organization or union with e.g. ethical standards and certifications?

2) As a fundamental moral question, how do we feel about/what should we do about the millions of workers we personally displace and leave jobless through automation?

3) How, if at all, should the Internet be regulated? Is it a utility? Antitrust?

4) Immigration and outsourcing technical jobs.

5) What should happen when law enforcement demands information that is protected by encryption? Should encryption that the FBI cannot break be allowed?

6) How should copyright and IP work with respect to software, algorithms, APIs?

7) Should developers be held accountable for writing software that leaks data? Should users have fundamental rights to their own data? Privacy?

8) Regulations on IoT devices like cars

The list can go on and on and on. While I'd agree a thread on climate change might not be particularly insightful or interesting here, it is crucial the tech community discusses the issues above regularly so that when a bill is put forth, or input is elicited, there is an actual community of experts that present a (reasonably) united front, who have discussed these things amongst themselves.

If we had banned political discussion on HN and sites like it, SOPA would probably be law right now. It was stopped because the entire tech community discussed it constantly, came to an agreement that it was bad, and took extreme collective political action against it.