Actually, we give a lot of thought in defining sane default alarms for most of the data sources that we have.

We want our users to get 80% of the value with 20% of the effort.

It's an opinionated approach that liberates a lot of users from having to setup and maintain everything.

I think you took a lot of flack in the original comment[0]

The alarms in netdata resolved a long-standing network issue on one of my boxes, and have variously alerted me to problems I could resolve with storage which greatly improved performance on my largest volume. On my other box, one look at the graphs alerted me to the fact that the entire SSD for my bcache volume was going unused[1]. I then used them while altering configuration and working with the drive to ensure the cache was being filled in a manner consistent with what the volume stored/how it was used.

The more I think about it, I might not have been as enthusiastic in my original comment as I should have been. It's been very helpful to me. I don't usually keep things like this running for very long (it wastes cycles on aging hardware...that isn't heavily used, but hey, it's the principal!) but I've kept this around because every time I've thought about removing it, I've visited the dashboard one last time and found something there that made me keep it.

[0] Though, as I mentioned, I'm not a sysadmin; I have a lab that might indicate otherwise, but I don't get paid for it.

[1] I had reloaded the machine/redone a previous configuration that included bcache and it screamed; I knew my new setup was much slower but I had forgotten about it until netdata made it obvious, again. I can't remember what I had to do to fix it, but it had something to do with the policy used to determine if a file should be put into the cache, and I think it was related to the fact that the cache was added to a volume with data present that rarely changed.