> If the DB is determining the schema and your code just mirrors it, you will inevitably do things like triggers, stored procedures, etc. that essentially put application code inside the DB. This makes testing and maintenance of such things all but impossible

If testing and maintenance of database objects (tables and other relations, as well as procedural code in triggers, SPs, etc.) is "all but impossible", the problem is with your DB maintenance policies and practices, not with where you are putting code.

It may be the case that lots of places have bad database maintenance practices (just as lots of places have bad maintenance practices for non-DB software), and it may be that in those environments, when you have a limited scope of influence, routing around those bad practices is the best solution. But it is a mistake to present that as a general solution.