I wisth they do not put up funds to signal. It is closed ecosystem. Even traditional phone calls are more open (having federated independent operators and interoperable implementations).
In short, federation makes a lot of things more difficult, and Signal opted not to do that to get a polished product quickly. Still, it's not either-or. As I remember it, Moxie welcomes the Matrix developers to try their approach and would be glad if they can get it right, he was just worried that it'd basically never lift off.
I think it's not bad to donate to either project, it's a good thing that we have both.
