I have done a lot of analysis on this, and the conclusion that I have found again and again is that Richmond's talent level under Mooney has been extremely low relative to the rest of the A10, but Richmond seems to get much more out its players than it "should" on a consistent basis.
Richmond currently ranks 13th in the A10 for average player ratings (
http://www.verbalcommits.com/conferences/atlantic-10). These ratings can have huge variance on an individual player level, but as a team wide statistic they are predictive of performance. We have been in the bottom 4 of the A10 in terms of talent level for as long as I have been following recruiting. Just looking at the past 7 years, Mooney has won ~53% of A10 games, where the expected win % based on the recruited talent level is ~30%. The difference between expected and actual performance is extremely large for Mooney.
This is the crux of the situation. Even though Mooney's teams outperform their talent levels, they have not been able to completely make up for the lack of talent. Recruiting is part of being a good coach, so the question for me has been is the recruiting problem completely on Mooney? Or are there institutional barriers that have hampered Mooney? If there are institutional barriers, how big are they and could a different coach overcome them? Are we working towards getting rid of these barriers if they exist (practice facility, new AD, etc)? These are all questions that I really don't think any of us know the answer to.
If the recruiting problem is mostly on Mooney I would say on the whole he is not a good coach since his recruiting deficiencies overshadow the aspects of coaching which he is good at (and since he gets more out of his players than he should I do think he is good at other aspects of coaching).
This is a very cold, mathematical view of Mooney's coaching based on a simple empirical model of team talent level vs team performance and it could be completely wrong, but it is the lens through which I view things. I'm looking forward to seeing some analysis from other posters on the board.