Real-time decentralisation is the headline. Matrix allows you to host your own server, federate messages in real-time between servers, and still benefit from end-to-end encryption between multiple client devices.
That isn't true at all - Matrix has a rich and growing ecosystem of chat clients. For Slack clones, you're well stocked, but the links given to you by the parent shows there is much more out there.
Thanks for pointing this out - the website is updated now to include poljar's work. (We did feature it on the blog but important to keep the projects list updated too!)
There are several competing Python libraries, those you mentioned plus https://github.com/tulir/mautrix-python. We'll do a round-up and review of the options soon.
There is support in Mozilla Thunderbird - but as a chat mode, rather than email as you might be expecting. You can enable it by changing the value of "chat.prpls.prpl-matrix.disable" to false in the advanced config editor. Still, since it really just enables a chat client, another Matrix client might be better suited.
I have no particular loyalty to Instapaper, but their major feature over Pocket, for me, is sending a compilation to kindle as an ebook (Kindle sees it as a magazine, complete with TOC.) People have been asking for this feature from Pocket for a while now (http://help.getpocket.com/customer/portal/questions/286894-k...), but without much encouragement that it will appear.
1993? Probably fair to say a lot has changed in the last 20 years! I don't really follow EA closely, but even so they have a poor image (of what it's like internally.) Google "EA spouse" for a start, the resulting material presents them in a very poor light, even in the (poor) context of the games industry.
This post until the problem is at least acknowledged, let alone addressed. Took me a long time to realise the problem was real ("it's a meritocracy, everyone is welcome in tech!"), and now I can't stand to look at the comments in threads like this http://news.ycombinator.com/item?id=5279118 without cringing.
Good place to get started reading: https://matrix.org/docs/guides/introduction