I am not a matrix fan, but I have to point out that thunderbird has had IRC and XMPP support for ages so it is not out of character to add another open instant messaging service (using IRC or XMPP on thunderbird felt underwhelming, though, I was never sure who was the target for this).
> I have to point out that thunderbird has had IRC and XMPP support for ages so it is not out of character to add another open instant messaging service
Sure and Thunderbird should relegate both IRC and XMPP to community maintained plugins. Ultimately developer time is a zero sum game and Thunderbird is wasting finite resources on fluff while neglecting the core of what's supposed to be an e-mail client.
