I'm not sure if you're reading the whole thread here.
> well over 25% of the business income can be attributed to a Californian workforce
The argument is that the company in question had 0 total revenue. If you want to attribute 25% of that to a California source, sure, but it's still $0.
ok, he has 0 total revenue. No problem. Prove it and then everything is fine. How do you prove it? Fill an income tax return!
His complain is that he was "required that my business file an income tax return" . Which is part of proving how much money his business made.
But of course, a blog post is not proof of income. A properly filled out tax form is.
So yes: California absolutely wants you to show that the over 25% contribution by one (or more) of its resident(s) amounted to an income of $0. They are not going to take your word for it, because your word is no good: fill out the paperwork to prove your claim. If you don't, it would be far more reasonable to assume that your business had enough income to pay for their employee (which typically costs a company twice what they actually pay in gross salary), which by definition is a non-zero amount (because under contract law there has to be an exchange of value for a contract to legally exist: you cannot be contracted to work for free).
> well over 25% of the business income can be attributed to a Californian workforce
The argument is that the company in question had 0 total revenue. If you want to attribute 25% of that to a California source, sure, but it's still $0.