... allows any employer to fire you at any time, for any reason. Wearing mis-matched socks today? You're fired. Tough shit.
... allows any employer to 'reorganize', 'retitle' and cap wages for any reason. Stellar performance review? Doesn't matter - we don't think you need a raise this year. Or next, for that matter.
Without union power, companies can run their employees into the ground and the employee has no recourse. Indiana's Right to Work & companies here are downright hostile to their employees, in alot of cases - they don't care, there's a huge market of folks desperate for work.