My take was that they're talking more about a script kiddy mindset?

I love designing good software architecture, and like you said, my object diagrams should be simple and clear to implement, and work as long as they're implemented correctly.

But you still need knowledge of what's going on inside those objects to design the architecture in the first place. Each of those bricks is custom made by us to suit the needs of the current project, and the way they come together needs to make sense mathematically to avoid performance pitfalls.