Because only people who are engaging in cynicism can predict the future.
The answer, therefore, is not bitching on the internet about all the wet blankets who only see negative outcomes, but acknowledging that everything we know needs to end eventually including ourselves, and balancing optimism for the short term with cynicism for the long term. And thus discovering that a healthy cynicism for the future predictions is probably appropriate, unless you truly want to live forever and have infinite energy for everything. But that's a god.
From my perspective, negative expectations do have a higher chance of turning out real, but because negative expectations most often are just code for human misalignment. We have some philosophical, instinctual, or aesthetic (etc.) preferences, but then reality is always going to be broader than that. So you're bound to hit things that are in misalignment. It takes active effort to cultivate the world to be whatever particular way. But this is also why I find simple pleas to cynicism particularly hollow. It comes off as resignation, exactly where the opposite is what would be most required.
Naive implementations are easy and cheap. And, if these tools and their entire software tree is not open-source, we cannot verify it's security.
We just have to trust that the developers are good at what they're doing. When every company under the sun has had multiple data breeches, I'm not too keen to do that.
Open-source the entire stack, show me a few white papers proving it's cryptographically sound, then I'll consider it. Until then, we should do with these tools what they deserve: being shoved up the government's ass.