You wouldn't want the Signal brand to become linked to it.
"I'm on Signal, would you like to chat there?"
"What, on the MAGA Nazi app, are you joking? Of course I'm not talking to you there!"
Ideally you want a broad spectrum of people.
I know it shouldn't make a difference and people should base their views strictly on the technical and usability aspects of the app, but real life doesn't work that way. Perceptions matter.