Somewhat similarly, welfare was aimed at a tiny fraction of "the deserving poor" but was poorly worded/thought out and thus inadvertently changed the social contract and thereby actively grew the number of poor moms. At the time it was created, having a kid out of wedlock was strongly taboo. Poor single moms were thus mostly widows. The authors apparently could not imagine it becoming more socially acceptable to have children out of wedlock.
I worked at bigco for five years. Similarly shortsighted wording for contracts and the like is pretty rampant from what I have seen.