It's a mistake to use one specific computer science concept (RDBMS) to solve 50 different problems. They mentioned logging and scheduling, two things RDBMS are not designed for and have specific limitations around. From just a general architecture perspective it's literally a single point of failure and limitation for every single aspect of the system. And it's vendor specific, it's not like you can just plug plsql code into any other RDBMS and expect it to work. It's so obviously a bad idea it's hard to comprehend taking it seriously