Governance of banks in a post crisis world

With the continual pace of governance change directed at the commercial banking industry, I am drawn to an article penned last year by Simon Johnson, professor of MIT's Sloan School of Management and former chief economist of the IMF entitled Boards on the Backs.

This article can be found at http://www.project-syndicate.org/commentary/jamie-dimon-and-the-docility-of-big-banks--boards-by-simon-johnson.  

Johnson argues that the financial crisis and its aftermath has exposed a series of corporate governance failings at megabanks and presents one big example to support his arguments - JPM's London Whale incident (contrasted with the JPM CEO/Chairman duality role which doesn't sit well with all governance observers). 

Johnson posits there are several underlying rationale for these failures, including:

1. Most importanly, the large market capitalisation/float of commercial bank stocks mean there is no market for control of the largest of banks and further suggesting (in effect) that large banks are now effectively protected from market discipline, a central tenant of corporate governance theory,  
2. Board members, and perhaps notably NEDs, lack sufficent expertise in complex risk and busienss issues that only a full time professional can attempt to master.  Johnson argues for example that only a fully qualified expert may ask the really hard, driving and probing questions of a CEO when evaluating a risk issue,  
3. The relative ease of which regulators establish criteria for US (for example) board members, 
4. The tension between a regulator's tough love and impacting the flow of credit to individuals and business, 

In short, Johnson believes may large banks have become possibly too large to regulate and govern.

As someone involved in financial services with experience in banking, I am not sure about point four noted above. Different regulators will feel (or not feel) different pressures but many are simply doing thier job as best they can. Also, these are good questions to raise but where are some of the answers, some might ask?  However we should note Johnson's overall position as one that resonates with many in supervisory positons and oversight as well as the general community at large.