The best line I heard, from a team lead that wouldn't back a "don't implement a task queue using postgresql", was "because I don't understand it/am not familiar with it [the alternative solution, RabbitMQ/whateverelse Q], we're not doing it". Other times it's just silence and, then, in an email or through somebody else "we don't want to do the incorrect solution". Without offering alternatives or what's "incorrect" about them.

These are common scenarios in mega corps. The above couple of anectodes were from one of the largest payment processing company and one of the largest b2b security company.

Oh, and you'll forgive my endless rant, the best one was out of some multi-billion nasdaq blabla company: CTO was absolutely ADAMANT how to implement encryption at rest. Using some tool from his college days. But, that tool wasn't maintained for years and didn't make use of Intel's AES-NI. Even though we explained him about latter, showed him the numbers using simple Linux tools, he kept scheduling meetings "to show us". Needless to say, using Intel's AES-NI was a good approach, compared to software-level encryption. Absolute waste of a couple of weeks.