I disagree. Coding an algorithm is completely different from using it as a black box to design and implement a system. Algorithms are fraught with conditional logic, where well-implemented systems tend to quarantine conditionals to make edge cases as few as possible.

An algorist prides herself on ability to optimize the problem space, where a systems coder prides himself on the ability to keep systems bug-free and free of accidental complexity.

There are many coders who do both, but I don't think the set of algorists is identical to the set of systems coders.