Republicans are oft thought of as pro-business. Not so. Their interests begin and end with the money and power they and their clients can accumulate, and protecting the booty from others. Any benefit to businesses is strictly a secondary concern.
Over and over again, the right applauds actions which militate against a confident, stable middle class, in an economy around 65-70% driven by consumer spending. They object to regulations even desired by businesses. They fight even the most incremental approach to removing the burden of health care from businesses. They value short-term gains over long-term. They don't see anything wrong with IBGYBG ('I'll be gone; you'll be gone') thinking. Actually building something of value? Not the highest of priorities.
Stock markets do at least as well, if not better, with Democrats in power. There's a reason for that.