Then why would you recommend a solution that hasn't even enabled end-to-end encryption by default?

When did I do this?

You recommended Matrix in your blog which, according to the first comment in this thread, is not end-to-end encrypted by default (which you acknowledged in your first response). Why would you recommend that instead of Signal?

Oh, I should have caught that and addressed it in my earlier response. Matrix is end-to-end encrypted by default on clients that support it. The valid criticism is that some clients don't.

Because for some that's not a show-stopper.

In the context of this article, framed as an alternative to Signal, I think it should be.

Why?

Let's compare it to F-Droid: He isn't saying that Signal should be distributed via F-Droid by default, just that there should be the option. So the article doesn't seem to say that the defaults are what matter.

But in the article he's saying not to use Signal because he doesn't consider it secure enough, and to consider Matrix as an alternative. His criticism of Signal has nothing to do with defaults, and everything with security.