I assume that the comment at the end - that this vendor tool was probably a hurried, barely-documented port of a DOS tool (which would have been safer 'because DOS doesn't do anything') - is probably right on the mark.
Developing software in a corporate environment under the constraints of capatalism often means average management and average coders both with a tight deadline.
Trying to take shortcuts in such an environment is only human nature, and getting non-optimal designs and implementations then should be no surprise.
The complete opposite is fixed requirements specifications and many layers between devs and users. This will get expensive and easily quite mediocre when devs know they are not really building the product the end user needs since motivation so easily falters in such an environment.