The same reason people rob banks...that’s where the money is!
It is easier to get a job in a RTW state.
I was born and raised in Michigan, and finally moved out after living there for 40 years. After witnessing industry after industry being decimated by outsourcing, including the ones I worked in, I finally had enough. The economy there is a shell of its former self, and the industries will never come back. And what work that is there is taken up by boomers working in service industries, and illegals who are swamping southeastern Michigan.
RTW was too little, too late, and negated by NAFTA and GATT.
Not rocket science here.
The cost of doing business in a RTW state is less than a compulsory union state.