> If a member of my team actually proposed building a bespoke system for something that can be straightforwardly done in a spreadsheet, we'd be having some conversations about ongoing maintenance costs of software

All interviews are contrived / artificial situations: The point is to understand the candidate's thought processes. Furthermore, we're getting Bilsbie's (op) take on the situation, there may be context that the interviewer forgot to mention or otherwise Bilsbie didn't understand / remember.

Specifically, if (the hypothetical situation) is a critical business process that they need an audit log of; or that they want to scale, this becomes an exercise in demonstrating that the candidate knows how to collect requirements and turn a manual process into a business application.

The interviewer could also be trying to probe knowledge of event processing, ect, ect, and maybe came up with a bad question. We just don't know.

Given that Bilsbie can't read their interviewer's mind, there's no way to know if that's what the interviewer wanted, or if the interviewer themselves was bad at interviewing candidates.