And Hawaii. See the general excise tax. Fun fact: it's a recursive tax on business revenue (not profit), so if you gross up prices to pass along the tax to customers on a transactional basis, you also need to pay GET on the gross up, ad infinitum. For example, on Oahu this results in a final grossup of approximately 4.7120% (starting from a base GET of 4.5%).
Are you referring to the B&O taxes (seems to be based on industry) or are there others around as well?
I could imagine some reasonable arguments for having a low tax like that around.