I think it's cultural. Managers today do daily stand-ups, one-on-ones, retrospectives, syncs, and all kinds of meetings. They are heavily invested in the day-to-day operations of the team. The societal expectation for this role is that they are hands-on, and when a problem arises, they will immediately do some shuffling or reshuffling to address whatever problem is at hand. In a sense, this is the outcome of agile-like methodologies spreading in the industry. If this is the tool we are teaching managers to use, of course it's the tool they are going to use.