Committe architectures

I have observed that sometimes an architecture tends to get defined by a committee of all stakeholders (or representatives for them) rather than an architecture team. This in itself may not be bad but there are some things that seems to happen when this is the case:
First the architecture tends to be defined by a set of separate decisions that solves separate problems the stakeholders have. There is no overall vision of what the architecture should be. A lack of what Frederick P. Brooks call conceptual integrity.
Second the balancing of quality attributes seem to be an average of everything. The architecture is not really good on anything (maintainability comes to mind). On the other hand no quality attribute seems to be totally forgotten or neglected.
Third the description of the architecture is done at low level, e.g. a design or implementation level because this is what a majority of stakeholders are used to in doing their usual work.