@Rusty Nails, there's always been some rogue management element, probably the case in most organisations, but it grew quite large during the late 90's and 00's. A few of the idiots managed to get high enough up the ladder that they then started promoting more idiots in their own image. Things have improved somewhat again now, as the bully boy style of management is indefensible in PR terms, and increasingly results in litigation. It's getting too risky both financially and reputationally to tolerate too many such characters in any organisation that values it's image. A lot of the dross has seen the writing on the wall and taken payoffs over the last few years, but unfortunately some really good managers whose experience and positive attitude were valuable assets have gone too.
More worryingly, some of the latest management intake are showing signs of turning rogue as their lack of job knowledge means they often fail to perform, then they resort to getting snotty and bossing their people around because they have got senior management on their backs demanding unrealistic results.
"Meet the new boss, same as the old boss" as the song goes....

In 35-odd years I've had a few truly outstanding guvnors, a few harmless but unremarkable ones, and a couple of out and out c**** that I would happily take a baseball bat to without a second thought. The really shite ones never stay long in one role, they cause too many problems and soon get shuffled sideways for damage limitation! Unfortunately they very rarely get sacked no matter how useless they are, unless involved in serious financial fraud or found with hardcore porn on their laptops.
As you say, the best managers are the ones who mostly leave people alone, support but don't meddle, and can motivate staff to do their best. My most recently retired one was outstanding both in job terms and on a personal level, and will always get an invite to future works drink ups. Jury's out on my new boss. On the plus side he's not a dick, but time will tell if he can be as good as the retiring guvnor, the bar was set pretty high.