As a designer, I'd say that is the problem with all design and not just bitcoins.
On one hand, there are skilled artisans who can create well formed and intentional brands.
On the other hand, you have Do-it-yourself movements where technology empowers anyone to do anything they want and still output a result that only a few years ago would have been prohibitively expensive or technologically impossible.
Desktop publishing made anyone with a computer a designer. Print on demand made anyone a publisher. Cheap audio hardware gives everyone access to quality that would have been unattanable only a few years ago. Digital photography put photography in everyone's hands for cheap. To follow that pattern, bitcoins makes anyone a financial institution?
Say right now I, or someone else with design skills, were to create a set of brand standards and design templates for bitcoin. That removes a lot of the DIY as now someone who can't follow those standards should essentially hire a designer who could match the standards or else their product doesn't "look correct" or even "unreputable/shady."
If the point of bitcoins is to resist a centralized authority, the concept of a single brand standard is against that.
I liked where you were going, but I think you've thrown the baby out with the bathwater.
Bitcoin is a voluntary decentralized system, with an emphasis on the
voluntary. The people who made the original ones chose the easy depiction and it was
good enough for the community it served so they adopted it at large. If you as a professional designer were to come along and contribute a design to the larger bitcoin ecosystem, then people would have the choice of picking your professional depiction or the one they've been using up to this point. Many of them will likely choose the more professional depiction, because it suits their application best while others will like the amateurish Coin.
The point is, your choosing to design something and introduce it as an option for people to use increases our choices, not the other way around. Just don't make a super awesome bitcoin design and then release it under a restrictive license.
Right?