I am afraid that "simply untrue" does not convince me, nor do your links which do not address the difference between NAS drives and those made without that designation. Your links only address the difference between manufacturers, not specific models.
Most NAS drives have a 3-year warranty and that's the biggest difference vs. regular (desktop grade) drives. If you're using multiple drives in a mirrored RAID configuration (which I highly recommend for a NAS used to store critical data), it shouldn't make much of a difference as long as you replace a faulty drive right away. Both are consumer grade hard drives and *will* fail sooner than later.
I always use regular drives and replace them every 2-3 years (although not all at the same time). Because newer drives are usually bigger than older drives, my NAS continually grows.
Oh, and I'm using a cheap $100 4x hard disk enclosure that's connected to a Banana Pi (like a Raspberry Pi on steroids) via eSATA. Total cost is roughly $150 including the Banana Pi, power supply and cables. And I get to use the ZFS file system on Linux which is a good thing because ZFS has been designed with a priority on data integrity.
Also, I keep backups of my most critical data (pictures, videos, scans of important documents, my own recordings) on separate hard disks off-site.