Comment by beatgammit

Since everything is open, you could probably run your own builds and use your own update server. Or you can use their code as a starting point and port whatever Linux distribution you want to it, which is a lot easier than a locked down Android or iOS device. And since it's so easy to replace everything, they need to maintain the community's trust since everything is in the open.

The best part is that I don't really need to trust Purism, I can choose to trust the community instead to whistleblow if Purism breaks the community's trust. Their target demographic is exactly the type that will be watching over their shoulder to make sure nothing fishy is going on.