Seems the determining factor is which entity would provide a broader opportunity for taxation, the existing Costco or the new admirer of the property.
Public Use was broadened to include increased tax revenue but it is not exclusive. Seized properties could also be for bird parks, duck ponds, dog pounds, just about anything a local council could define Public Use and benefitting the public to be. The ruling reserves the decision of what constitutes Public Use to local governments, not the Constitution. Ostensibly, whole communities could be forcibly rearrainged to a more favorable composition as determined by the local governments.