Answer: The culture itself is at fault. A blanket prohibition against
"negativity" may keep some from admitting it and inebriation may keep
them from thinking about it, but human nature can't be denied. When one
person finds that he has to lick another person's boots in order to
not be beaten up (or expelled, or suffer some other unacceptable loss)
and he has to look happy about it, no matter how much he may go into
denial about it, he's going to resent that. The only thing that
suppressing awareness of what it is that he resents (by convincing him
that he has no right to resent it) will achieve will be to turn his
resentment into a free floating rage, always looking for something to
attach itself to, and never satisfied for long because it is never really
addressed. This is part of what is wrong with "don't worry, be
happy", a normative attitude in the "white bread" mainstream of
American culture which is only going to be reinforced by the
strangely evangelistic apathy which marijuana seems to promote.
This attitude, straight out of the commercially published "The Power of
Positive Thinking" by Norman Vincent Peale with maybe a touch of "How to
Win Friends and Influence People" by Dale Carnegie, is very convenient
for a corporate world which likes its workforce docile and found, to its
undoubted joy, that political conditions in the New World (including a
trendy and more than slightly intolerant rejection of Old World
culture) gave it an opportunity to remake the culture in its own part of
the world to its own liking. And what would that liking be?
Think about what the defining characteristic of a corporate executive
is, that which made him the man he is, today. It isn't professionalism.
Hard working, talented people languish in obscurity for years. It isn't
ability. The half-witted manager is such a cliche that I won't even bother
to digress on that point. I'll just point the reader in the direction of
the nearest book about Dilbert. 
The defining trait of a corporate
executive is an overbearingly aggressive thirst for power, and it is that
trait that allows him to run roughshod over his competition as he rises
to the top in a bureaucratic system in which advancement is based on
politics, not on results, because results in such subjective areas where
so much teamwork is involved are hard things to quantify. And if your
driving urge is a thirst for power, what is the one thing that is
going to get in the way of quenching that thirst more than anything
else? Assertiveness out of the people one is dealing with. And thus,
you will love the concept of people being told that they should be
positive "no matter what", because on those terms there is no way for
them to assert themselves and question the status quo you are creating
for them.
Like alcohol abuse, such a willful shutting down of one's own critical
faculties, while it does make for appalling results, has a way of
maintaining itself because life starts feeling a lot worse for a while
before its starts to feel better when the addict puts away that to which
he is addicted - here, to the illusion of happiness which willful
obliviousness offers. The first thing that the groupthinking "go along to
get along" type is going to be confronted with, should he start thinking
for himself, is just how stupid he has been. If, like a number of the
people you saw in the account of the silliness
I saw in the Burning Man forums, he is not too bright by nature, this
is going to hitting him on a sore point, and for him to retreat back into
the illusory safe and warm embrace of the group will be all too easy. And
thus, while this artificial culture has been created in order to make
him (and others like him) more easy to take advantage of, our "Joe
Sixpack" will fight to keep it alive, becoming an accomplice in his
own exploitation and wondering why others view him with scorn, even as
he makes yet another feeble attempt to browbeat his intellectual
betters into letting themselves be exploited as well.
Now, how would you describe the behavior seen out of BMORG which, for
example, has gone on the attack because of the creation of a Chicago area
burners list to compete with their own, and which the aforementioned Playa
Phone people have expressed concerns about, citing a fear that BMORG might
attempt to take over their operation? One which tolerates no dissent from
its opinions on its boards, even as it tries to cover up the reality of
its own censorious tendencies by making vague, hand-waving allusions to
"harassment" on the board, stonewalling anybody who asks them for
specifics on what form that alleged "harassment" took? One which has
taken control over what, by its own account, was a gathering of anarchists
out in a place remote enough for those present to be left alone? This is
power seeking, corporate behavior seen out of people from a vacuous,
corporate dominated and defined cultural background. Having created a
parody of their own unwholesome cultural roots, they have lead their
followers into an exaggeration of its own unwholesome cultural
implications. The hard core burners are just like the American
mainstream in the worst possible way, only more so.
It's enough to make one throw a party, just to celebrate the fact that
one is a relatively unassimilated ethnic.