>top-tier engineers are not generally qualified in terms of non-technical requirements

It's just that both sets of somewhat orthogonal skills are less likely to reside in one person.

An analogy from baseball is why are pitchers generally lousy hitters (even pre-DH)? Did they get less practice? Probably. But it's also the case that (again even pre-DH) any ability to do more than lay down a bunt was absolutely a nice little bonus but their job 1 and 2 and 3 is pitching the ball.

On the other hand, even the best fielding shortstop in the league still needs to have a half-way decent batting average, even if they can get away with a lower one than other positions.