For most development roles that I have encountered, the technology seems to be most important. However if you want to move into business, product, or management, then an understanding of how the software will be used becomes hugely important.

If you fundamentally understand what problem you are solving beyond simply the technology then you can answer questions like "what feature should be developed first?" or "how should we organize our data for the customer?"

You can definitely build a career out of being "just a programmer" and that is what I have done. However being a "clueless developer" is limiting and very successful people tend to have a mix of both code and industry knowledge.