The proposed legislation, unfortunately, could have the unintended consequence of making it harder for all Americans, regardless of sexual orientation, to find jobs. It might encourage frivolous lawsuits designed to win big legal fees, not to promote equality before the law. To that end, it would increase the cost of doing business, partly because of the cost of these lawsuits. When costs increase, employers are less likely to expand their businesses and thus less likely to hire more employees. Because the legislation would protect classes that are subjective, legal uncertainty and costs could be particularly acute.So the reason we can't protect LGBT Americans from bigoted employers is because it might cost too darn much money, and because if employers can't be bigots in the precise ways they want to be bigots they will bring our economy down out of spite, and because certain religion-touting bigots don't like it. Well there ya go, there's the very definition of Republicanism.
Further, the legislation could impose undue burdens on freedom of religion and association. It does purport to include religious-liberty exemptions, but these “protections” have been litigated repeatedly in other contexts, which itself is burdensome. And that’s not to mention Barack Obama’s regulatory agencies, which have repeatedly shown hostility toward religious freedom.
It's very curious what things make it onto the Republican "too much money" list. There's been no crippling of the business community in the states where LGBT discrimination is already illegal, so enforcement costs involved in telling people they can't be bigots seem to be rather minor when put into practice. It would cost, say, probably about the same as five minutes of shutting down the federal government, or perhaps two-thirds of what it costs for Republicans to print up all the Benghazi paperwork for the eleventeeith time, or maybe about the same as the gas costs for ferrying John McCain to and from the Sunday shows each weekend.
I suppose it's the same reason we can't put the people who wrecked the world economy in jail. Sure, they were crooked, but "the market" just can't handle laws in which the business class gets treated like everybody else. It's much too expensive, you see, and once you tell the job creators that they can't be crooked, or can't enslave people, or can't use their employees as low-grade furnace fuel, or can't fire Tim over there simply because someone told you Tim might be a homosexual and you can't risk getting Satan Cooties from him—well now, if the business community can't do those things, how would America have an economy at all?