One idea is that class ownership is an organizational 
mechanism for use with a team of lesser experienced 
developers.  

The assertion is that a team of highly skilled individuals
tend to be highly collaborative and will develop a good 
understanding of their problem space.  Consequently, each
has the ability and understanding to alter, re-factor or
modify classes within their problem space as required. 
Whereas a team of lesser skilled developers can make use of
class ownership to help manage their development.

Is there a pattern here of diminishing returns for class
ownership as development teams become more skilled?

RicardoClements