Every time someone mentions raising the minimum wage, you get tons of businesses claiming that they'll have to reduce staff. It's just what they do. Anything that might require them to put more money towards the people who work for them causes them to start with the "reduction in staff" threats. So, this really has little to do with Obamacare. It's just business as usual.
And I say this as someone who has family members who run businesses, some of whom will actually be required to do something under Obamacare.