Is design about enabling or just rules

I was talking and walking on the mobile today ranting and raving about design-repression.
This is the bit of design where either the style guidelines are set down so tight you can't kern a character without turning heads or the studio is just populated by people who have forgotten the perks of working in the 'creative' industries.
This is the time when basically the design equivalent of etiquette, (even morality!) gets ugly. A hierarchy is established on an understanding of 'the rules'. i.e, mm precision on underlines and runarounds; military-style grids; unbreakable canons of image use; people who demand kerned back caps despite the fact that the result is physically unoticeable. It is pure, disciplined design.
The only problem is that (99% of the time) it's a complete waste of time. 99% of design is about enabling communication - someone else's communication. 99% of design isn't noticed (this is a good thing). 99% of design is thrown away within a week of production. (Yeah OK so all these 99's are made up - but it is an illustration not a literal truth).
SO. Given that all this design is actually for normal people, who shouldn't notice it, and will dispose of it almost instantaneously - why is design facism so prevalent? Why do we go beyond the reasonable desire that corporate graphic design should work as a collection, have high production values and follow house style? Why ruin your life with 'unbreakable' rules?
My own personal opinion is that it is our own form of office politics - how do you decide what's right and what's wrong in a relatively subjective field, how do you demonstrate hierarchical superiority, how do you keep junior designers in their place if there actually perfectly good? By enforcing a rule-system of absolutes that become so specific that you need to study to understand when they are broken. Rules that make NO difference to the product or it's effectiveness in the market. "High production values" easily becomes a rod with which to bludgeon or repress.

I'm not advocating bad design here; it's not an apologia for sloppiness. I'm just saying that designers should watch for when the feedback means something to the product, and when the feedback means something to reviewer.

I have had clients who live by the book and others who seem not to give two hoots about design. But the latter is learning design value; it's value is in bringing quality to their communications, not killing the fun in the name of consistency.