Hes joking, but honestly there are some things that should be treated this way. Showing up without consumables is just ridiculous, they aren't remotely hard to buy/farm/whatever and if you don't have them its nothing but laziness. Also, the people that show up to new boss fights without having researched the encounter and waste the time of everyone that did show up prepared.

So after a long day of work, your raid leader and all of the other well prepared raid members should show up to a raid that is unprepared, not on time, disorganized, doesn't play well, and won't listen to criticism.

And his post was really a joke...

I guess everyone missed the part where I said I've had raid leaders along those lines.... My first thought was certainly joke as well, only well, it wasn't quite that far from my experiences in the past.

Quig, there's also a difference between blatant yelling and humiliation of someone and having expectations of their preparedness. I've had people treat raids like I'm in the armed services. Guess what, there's a reason I didn't sign up for that in real life, and no I don't want to come home to be yelled at if I make a stupid mistake here or there. I generally try hard, do well, and fess up when I fuck up. I don't need someone bitching at me on top of that.

Office Space has a great quote on motivation:
I don't want to be yelled at, but I also don't want to raid solely not to be yelled at.

Some people mistake criticism for being yelled at also - and each person has their own tolerances for what they will accept. I will say personally I have never once in three years yelled at guild members, but I certainly do tease/mock people, and definitely get on people's cases for making mistakes. Calling people stupid or idiots is pushing the line - but calling people out for acting stupid or not being focused isn't in my opinion.

There are a few ways to motivate a raid. Negative consequences is one way to do that - and while we ourselves rarely use this method (sometimes for on-time DKP, or deductions for unannounced AFK's, and minor ones at that), other guilds do, and they do it successfully. I know this cause I was in an EQ guild that did this very well. There really isn't much of a problem with it... especially as most of these systems don't dock you for honestly msg'ing the RL with "Gotta afk for 5, brb". They're reasonable.

Another way to keep your raid focused is to have a raid leader who is a constant, active talker - someone who can instill pace and focus in the raid through communication and movement.

Your example is sorta off base.
Peter Giddons in your example doesn't want to be at work. If you don't want to be at a raid, you shouldn't show up.
This is a game afterall. If you're not enjoying it, you're only going to make it worse for everyone around you. I doubt anyone would yell like you're describing in a professional environment unless it was something really serious. Even then...

Something I feel is important to focus and progression: good judgement on the part of the raid leadership to not put people in positions where they are likely to fail. The leaders need to show the ability to start off a fight with a smart strategy, as well as demonstrate that they can adapt it quickly to the specific circumstances at hand in order to emphasize strengths or minimize weaknesses. For example, I've seen a raid that put the wrong tank on a boss (with several to choose from) for 10+ wipes before a raid leader got the bright idea that a different tank class could handle that boss better. By that point, tempers were frayed and there was yelling on vent--it was the sort of thing that should be worked out after three or four wipes, not ten. On the flip side, starting a new fight with a perceptive strategy usually means that when we wipe, it's clear to everyone that the wipe wasn't due to strategy but to individual execution. The moment raid members start questioning the strategy, the focus is lost; the more often the basic strategy changes as an indecisive raid leader throws darts at a boss hoping one will hit, the more quickly people will assume that the strategy, not their individual execution is the root cause of a wipe.

Raid leaders who handicap their raid (not intentionally, but often due to their overconfidence in their strategic insight) not only will create an unfocused raid, but they'll never really understand why the raid isn't moving like it should because in their view, they've done nothing wrong.

A corrolary to this: having too many type A personalities in raid leadership positions is a dangerous thing. A leader, by definition, must always be open to the possibility that what he or she "knows" may be all wrong. They must have vision, yet remain humble. Don't constantly second guess oneself, but don't always take a my-way-or-the-highway attitude either. Ultimately this is a computer game, not the army nor a corporate job--raid leaders aren't paying me a salary, so they've got to earn my allegiance through their demonstrated good judgement. It's not too different from leadership in non-profit organizations, actually, and very different from leadership in other aspects of life where there often is a carrot like salary to keep people around whether they're happy with the leader's approach or not. I suspect that many unfocused raids, particularly the ones with low morale, are lead by competitive type A raiders who can admit no wrong and thus blindly, inadvertantly lead their 24 followers down a path of wipe nights and endless frustration.