One of the many reasons businesses are fleeing is because of the CA income tax agency, the Franchise Tax Board (FTB). FTB sends notices to businesses demanding proof that whatever the tax they decided to impose isn't actually owed (and FTB does make up weird taxes out of thin air) within 30 - 60 days or else the tax will be due and payable and penalties will be imposed for "not paying." So the business responds on time with proof no tax is owed. FTB takes 95 - 202 days to process responses. So the tax liability and penalties are imposed for "not responding" when FTB had the response on time. And once the tax is imposed, there is no getting it removed. There is also no due process to go to a judge prior to the imposition to say "Hey, I never owed this, I proved to FTB on time that I didn't owe this, and they violated my rights by not processing my response."

edit to add link to the processing times: https://www.ftb.ca.gov/help/time-frames/