I don't understand the assumption that a software developer should study computer science to prepare for a career in designing, writing, and delivering computer

I don't understand the assumption that a software developer should study computer science to prepare for a career in designing, writing, and delivering computer software. Consider the building trades. Employees in that industry don't study "Building Science". Architects study architecture. Engineers study engineering. Craftsmen in the various building trades study in apprenticeships. Why not admit that computer scientists should study computer science (a valid and useful area of study in its own right) and instead develop a full-fledged degree program for the various skills involved in the software-development industry?