I heard Michael Northrup, SVP & CIO of AmFirst say those words last Friday morning at the AlabamaCIO awards event. His statement made me think back on things I've and others have done because we could; however, upon reflection, we shouldn't have.
Excess is the main reason why. Specifically, excess can cause people and organizations to become excessive. For example, think about the number of bad, value-destroying acquisitions companies have done, in addition to ill-fated "Transformational" outsourcing, IT and other projects.
Personally, think about the bad investment decisions you have made. The question then becomes, "How to prevent becoming excessive?" The answer is a relatively simple one: Always, always have at least one person in your inner circle who is assigned to question your judgment. The key to success is to let that person know before--not after--you make decisions. Take GE for example, I recently read about a new board member who asked a long-serving one what they did when the CEO presented a new acquisition candidate. The response was, "Applaud". Needless to say, if it is true, that approach didn't serve the CEO, company, community, and shareholders well.
In closing, the more excess you come into, it is far better to have people around you who question instead of applaud.