WIth commercial properties it is strictly business, regardless of details, obviously. Actually, during the 80s, breaking non-mutually beneficial contracts, on the basis of a cost-benefit analysis, was touted as an advantage over Japanese business practices(which will go down with the ship to honor a contract). This has not always been the case in anglo-saxon economies, but has evolved over the last few decades as acceptable business practices. This was rationalized as self-interest being the highest moral possible in a Randian sense and as a definitive competitive advantage.
Residential strategic defaults are a very small fraction of all defaults. As of March, it was about 3% of total defaults. Interestingly, one of the biggest hang ups for upside down home owners is their personal estimation of home value and future projection. The lie to themselves. Which, I would bet, is the reason strategic defaulters are of a dramatically higher percentage, in the upper socioeconomic strata. They are better as estimating these things and probably less prone to self-interested propaganda. Second, is a tie between irrational fear of consequences and “old-school” honor. Though, when one is realistic about the value and future projections one would hold their moral responsibility to their family as a higher moral then honoring a contract that the holders of the mortgage so very publicly evaded those very same moral bonds.
With almost 25% of mortgage holders underwater and just less than half of them not paying their mortgages coupled with the fact that we are on the precipice of a double dip. You better believe strategic defaults are a systemic threat and on the radar of officialdom. Which is why Geithner just stated that Fannie and Freddie would be going after them.