Far be it from me to mess with you on tax law. Suffice it to say that NV ops have been established by at least THREE Wi. companies for the sole purpose of reducing WI taxable income: Kohl's, M&I Bank, and Manitowoc Co. I also KNOW as a matter of fact that two of the three deals were engineered by Deloitte (there were also some legal-beagles involved.) Last, WI wants a large chunk of money from Kohl's (the others will follow shortly.)
Suing large and prosperous WI employers is a helluva way to make friends and influence people. Won't take much for two of the three named above to simply move HQ out of WI, after the dust settles and the current officers retire.
Long story short: NV knows how to play the game.
The trick is to have a majority share ownership not residing in California. Than you are only subject to tax on California dervived income based on the unitary tax formula. Of course for ma and pa companies, where ma and pa live in California, none of this obtains. But that doesn't slow down the incessant advertising to get them to part with a bit of their money to the con artists.