[mrmekon]

I don't really understand your question here. NVM is non-volatile memory. Stick a filesystem on it and it's still non-volatile memory.

Do you mean they were writing configuration files directly to a known address in Flash instead of using a filesystem? It's much simpler and less resource-intensive and doesn't require writing and maintaining a driver. There are plenty of cases where direct-writes are better, and plenty of cases where a filesystem is better, and a nice big gray area in between.