In this case, the parent commenter would rather recommend that people use a less secure messenger so that he can sysadmin his own phone, and the Signal project has taken the eminently reasonable alternative position that getting cryptographic privacy into the hands of the vastly larger set of people who would never even imagine configuring an alternative app store takes precedence over satisfying the noisome demands of nerds on message boards.
You are of course welcome to use an alternate secure messenger for your own communications (I like Matrix just fine for what it is), or, for that matter, to stand up another instance of Signal, which is open source; there's a whole community of people who apparently do this.
The problem isn't simply that people disagree with Signal. Disagreement is fine (though recommending a "secure messenger" that isn't E2E by default is security/privacy malpractice, for whatever that's worth to you). The problem is when people can't metabolize disagreement and insist, repeatedly, over the span of years, that any disagreement must be evidence of malign intent.