They've just declared in court documents that having a pro team does nothing to help the city's economy. Pretty much all NBA teams claim the opposite when trying to get taxpayers to finance a new stadium.
"The financial issue is simple, and the city's analysts agree, there will be no net economic loss if the Sonics leave Seattle. Entertainment dollars not spent on the Sonics will be spent on Seattle's many other sports and entertainment options. Seattleites will not reduce their entertainment budget simply because the Sonics leave," the Sonics said in the court brief.