Totally agree. In my experience "that's just X it does that sometimes" have been symptoms of some of the scariest bugs in the system we've been working on. A couple of examples:
- a caching issue that was a "just X" on a single server, but took product search (and by extension most of the business) offline if two servers happened to encounter the same problem at the same time.
- a "just X" on user logins, which turned out to be a non-thread-safe piece of code that resulted in complete outage of all authn/authz-related actions once demand hit a critical point.
On top of that, having a culture where there are errors it's okay to not fix is tremendously damaging to team values. I've not seen a team with this attitude where the number of "just X" errors wasn't steadily increasing, with many of the newer ones being quite obvious and customer-affecting problems.
- a caching issue that was a "just X" on a single server, but took product search (and by extension most of the business) offline if two servers happened to encounter the same problem at the same time.
- a "just X" on user logins, which turned out to be a non-thread-safe piece of code that resulted in complete outage of all authn/authz-related actions once demand hit a critical point.
On top of that, having a culture where there are errors it's okay to not fix is tremendously damaging to team values. I've not seen a team with this attitude where the number of "just X" errors wasn't steadily increasing, with many of the newer ones being quite obvious and customer-affecting problems.