I have a degree in both Computer Science and Civil Engineering and I disagree with the analogy of the Product Manager writing the feature likened to them welding. Writing a feature can be really complex, and or simple depending on the requirements, however the analogy of welding misses the importance of domain and technical knowledge required in implementation.

Writing a feature is more like a Project Engineer managing and overseeing human resources in order to realise the design. Project Engineers understand the design and may even partake in in-situ tests, like concrete slump testing to test if the concrete mix is acceptable. And yes, Project Engineers are Civil Engineers who specialise in construction. So if the analogy needs to hold for this article, Managers too need experience and formal education in Software, but that is not acknowledged in this article.