[jjoonathan]

My guess is that the language's "day job" uses many similar-but-ever-so-slightly-different intermediate variables which are difficult to descriptively name in any manner that facilitates understanding faster than just re-reading the definition. Long descriptive names have a concrete cost: they impair your ability to recognize visual patterns / turn common compositions into "pictographs" and they don't refine well: instead of gaining an index and adding a bit to the definition the author has to come up with a bundle of new similar-but-slightly-and-meaningfully-different names from which someone else (including their future self) will be able to reverse-engineer the definition.

The shortcut of using descriptive names just doesn't have the same ROI in all kinds of code. The first time I was forced to abandon my descriptive-naming ways was when I started writing finite element solvers. I don't think it's much of a stretch to believe that (some areas of) finance have the same cost/benefit profile. Since this is a desktop programming example it's relatively easy to come up with good descriptive names, so the short names are almost certainly a holdover.

Or it's just a macho thing. There's enough pixie dust floating around this press release that I wouldn't be surprised.