Management performance measurement depends on KPIs. KPIs that don't look vague depend on measurability and/or visibility. Code isn't measurable. Functionality sort of is but it's too vague. Visibility often amounts to having a room full of people that you can see working. As a technical product manager, who uses a set of tools that make my work measurable, I don't have much incentive to make the team visible by putting them in a room with tables and no dividers. Managers who were never coders, and who therefore are flying blind when they say progress is being made are the ones that need a KPI dashboard and an open office.
The quest for measurability is also driving fake agile. The real measurement of agile is right in the manifesto, but if you can't read the code, you can't measure.
This. It's not (at least mostly) a power trip. It's mostly about control. They don't know how to control what they can't measure, and they don't want to have to trust people who can see what the manager cannot.
Agile... I've seen a good agile environment ruined in exactly that way. There is an "impedance mismatch" with upper management, because upper management wants their usual progress reports and burn-down charts, and wants them in the normal terms, and agile doesn't produce those... unless there's someone who has that as a part of their job on the agile team.
The quest for measurability is also driving fake agile. The real measurement of agile is right in the manifesto, but if you can't read the code, you can't measure.