I wouldn't expect a building architect to do a great job pouring a foundation, framing a wall, or running plumbing. But I would expect them to be able to do it, at least to a basic level.
Architects that don't understand how to do the fundamentals of implementing the designs they make tend to make unrealistic designs, that are expensive to implement and may look pretty, but function poorly for the owners and occupants.
This applies to architects of buildings, architects of software, and architects of hardware. Probably to most high level design and supervision type positions.
Edit to add: many of the best architects of buildings are able to do amazing things specifically because they've studied the fundamentals and are able to do innovative things with materials. Of course, time will tell it the innovation worked out well or not.