You know, you are right. It just totally ticks me off that people have jobs of high responsibility and they are flippant about it instead of taking their job seriously. I have family that are in the medical field and have taken call, where they have a specified amount of time to arrive after being paged. They get there at the absolute last minute and it really bothers me because someone’s life could be on the line. In this case, 17 people lost their lives and 17 families have irreparable damage and a community is forever changed because someone “didn’t do their job”. A simple termination is just unacceptable.
I have no particular insight into the FBI's caseload or workflow, but I do have an imagination.
I have a hard time believing that someone viewed these reports, shrugged "who cares" and ignored it.
I have an easier time believing that these reports were noted, assigned a priority and assembled into a database or document, and the highest priority reports given the most attention.
Should this have been given higher priority? Maybe. Probably. It's easy to say that in retrospect.
I expect we will know more at some point about how this actually did happen, but I don't feel entitled to details.