> If something needs to be fixed, why is it just a log?

What he meant is that is an unexpected condition, that should have never happened, but that did, so it needs to be fixed.

> How is someone supposed to even notice a random error log?

Logs should be monitored.

> At the places that I've worked, trying to make alerting be triggered on only logs was always quite brittle, it's just not best practice.

Because the logs sucked. It not common practice, it should be best practice.

> Throw an exception / exit the program if it's something that actually needs fixing!

I understand the sentiment, but some programs cannot/should not exit. Or you have an error in a subsystem that should not bring down everything.

I completely agree with the approach of the author, but also understand that good logging discipline is rare. I worked in many places where logs sucked, they just dumped stuff, and had to restructure them.