One possible reason is the inclusion of the b5.
In tonal music, scale-degree 5 is so vitally important as the basis of the dominant chord; it's of course this dominant chord that creates the ultimate tension that leads everything back to tonic. When a musical environment lacks this perfect fifth above tonic, the tonality it creates (or fails to create) is a staggeringly different one than one usually thinks of when s/he thinks of "tonal music."
(It's partially because of this reason that Locrian is often the "forgotten" mode---because it's the only one that has b5 instead of the perfect fifth.)
So it might come across as odd to call a scale "Natural Minor b5" (even if it technically is) because "natural minor" has such a clear connection to classical tonality (which demands that perfect fifth). With such a clear connection, it's almost an oxymoron to replace 5 with b5. It's a bit like a gym offering you a free extra large pizza when you're done with your workout; it undoes so much of your hard work!
In contrast, one of the most defining characteristics of Locrian is this b5. So when a collection includes this b5, perhaps it's best to list it as an adjusted Locrian scale (which has very little connection with classical tonality) instead of an adjusted natural minor scale (which does).
There's another possible reason: the scale in question is a rotation, meaning that it's a scale collection that begins on a scale degree other than the tonic of a parent scale (here, C jazz minor). We're fine with the notion of a Locrian mode as being a rotation (it's the seventh mode of a major scale), but we tend to think of natural minor less as a rotation and more as a bona-fide scale based on its own tonic. (It's Aeolian, so it is a rotation, but there's also an entire tonality based off of it, so this is a different case.) This may be another reason; since this scale is a rotation, let's base it off of another rotation, not off of a more familiar tonal scale.