I completely agree. Leaving a gap and waiting for someone to fill it is practically the
opposite of management.
> ..once employees know this is a short cut for promotion, they will focus a lot of their energy and attention to find 'the void' and try to fill it, or act like they can fill it, thus neglecting the real work that need to be done.
This in particular is really dangerous because it can poison an organisation's culture. For example, imagine Ben decides to focus on managing upwards in an effort to get Adam to promote him. Meanwhile, he neglects his duties, forcing his team-mates to pick up the slack. They start getting annoyed at Ben because he's not pulling his weight.
It's not uncommon, in my experience (and I'm aware that I'm at risk of stereo-typing here), for good, smart, conscientious people in technical roles to focus first on doing the job that they've been assigned and trust that management will recognise and reward them for doing so (and, conversely, punish anyone who slacks off), and that one of those rewards is that they will be considered for any opportunity for promotion that arises. Unfortunately, that doesn't always happen.
If Adam promotes Ben, his old team-mates are going to be really pissed off. From their perspective, Ben's bad behaviour has been rewarded, instead of rectified. Meanwhile, the extra work they've been putting in to make up for that bad behaviour has been completely ignored.
The end result is an unhappy team, They'll resent both Ben and Adam, their productivity will probably drop (because whey the hell should they work their asses off when they're clearly not going to be rewarded for it?), and may well start looking elsewhere for work.
In that scenario, Adam has not done a good job as a manager, and he's definitely not a good leader.
There's nothing wrong with identifying a gap and opening a dialogue about how it can be filled (including asking if anyone's interested in filling it) but if someone moves to plug a gap, that generally means that they're going to leave a gap somewhere else. A good manager needs to make sure that they understand the implications of shifting people around, and explicitly recognise the indirect contribution that Ben's old team-mates are making to fill the gap.
Organisations are about teams, not individuals. It's astounding how many managers fail to grasp that.