FASB doesn't do its rule making in a vacuum. It solicits (and mostly ignores) comments from a wide range of stakeholders. The result is a rich set of data to examine the role of large institutions in shaping the rules that govern them. The result is language like this:

We believe that certain aspects of the proposed FSP fail to meet the Board's objective and would, in fact, increase the difficulties experienced by preparers and auditors by limiting the number of data points that preparers may consider in making valuation estimates. In addition, we are concerned that the example provided in the proposed FSP is confusing and may lead to conclusions that are not consistent with the concepts and framework of Statement 157, further resulting in significant inconsistencies in the fair value measurements estimates for the same financial instruments among various preparers.

Which should properly be read as "This fucking mark to market stuff is killing us!"
Deutsche Bank Letter To FASB, March 27, 2009.
SIMFA Letter To FASB, March 27, 2009.
Citi Letter To FASB, March 30, 2009.