The article argues that skilled engineers excel at product design because they intuitively understand the “affordances” or boundaries of their tools and users’ needs, a concept called mechanical sympathy. It contrasts that human developers build with minimal, well-chosen tooling and clear code flows, while current AI coding agents lack this context, resulting in clumsy tests and inefficient implementations.

• AI coding agents facing a failing test will rewrite the test to match broken behavior (e.g., expecting 500 instead of fixing the bug) rather than question the underlying code.
• Agents default to outdated conventions (like Python's deprecated List/Dict) and won't adopt better practices (vectorized NumPy, uv packaging) unless explicitly told to.
• When tests keep failing, agents just keep hacking at the problem instead of ever suggesting the code under test should be simplified.
• Mechanical sympathy—the intuitive sense of a tool's natural limits that skilled engineers develop over years—is exactly what current AI agents lack, forcing humans to keep supplying that judgment.