eranb I'm looking for evidence that I can trust netbsd like people trust centos.
I don't understand your point.
Companies who choose CentOS want RHEL for free. They don't specifically trust CentOS, but rather a committed Linux distro vendor (Red Hat). Others trust Ubuntu for the same reason, it's just that their taste differs on some details. However, both camps choose a Linux distro because they know it will do the job and they will be able to easily find Linux skills. They don't have to invest in research, testing, proof of concept, training, learning curve, etc.
Linux is backed by the biggest market caps on Earth (Google, Amazon, Facebook, etc - even Microsoft!) because they use it for themselves and they want to make sure it will always fit their needs. This means that if your company is smaller than theirs and you choose Linux, you're assured your technical choices will not limit your growth.
An individual or a small company weighs nothing compared to Google and the like. If you have a specific need or want to contribute, your voice will not even be heard beside those giants - they don't event notice you exist. So you have to go their way, full stop. But again, it might turn to be a good thing for you, it all depends on what matters the most to you.
The BSD family is all the opposite of this. Its OSes are developed by hobbyists, or rather amateurs - stemming from the Latin word for "to love". Although the BSD OSes can be used for mostly the same tasks as Linux, you don't choose to use a BSD because it is better or more trustworthy than Linux, but because the values of the community of the BSD flavor of your choice better suit yours than any other OS.
This is why you can't get any kind of "evidence" in the BSD world, it's really not a matter of technology. People who choose a BSD OS do so because they prefer to feel like a craftsman rather than an anonymous, specialized worker. They want to build cathedrals, not factories.