Have you ever read the contraindication list of a medicine? It is the same kind of trade-off. Someone can choose to use something in a "mission critical system"

Have you ever read the contraindication list of a medicine? It is the same kind of trade-off. Someone can choose to use something in a "mission critical system" (whatever that is) because the alternatives are worse, not because the chosen solution is perfect (that does not mean I would advise using PostgreSQL - just accepting that it can happen). On the other hand "quirks like these" are the reason you should not update too often mission critical systems.