Yes, HuffPo is leftist, but I don't see how rage over this particular issue has jack-all to do with where you lie on the partisan spectrum. I'd expect even many full-bore libertarians to find that policy stupid, discriminatory or both (though they would more fully support an employer's right to be as stupid and discriminatory as they wish).
I think those characterizations are rather context-dependent, though. Restating my point somewhat differently, the "what should be done about it" reaction lies on a somewhat independent axis from the "how angry am I about this" reaction.
For example: A business that refused to hire gun owners would probably get a far more rage-filled reaction from a rightist than a leftist, but it's very roughly analogous.
I look at it as a self-correcting problem. It's a brain-dead stupid HR policy and firms that adopt brain-dead policies will eventually be beaten out by firms that don't.
At the risk of turning this into a political argument... your characterization of the left is simply untrue. A 'leftist' (whatever that means) would most likely view business with a measure of caution, preferring a regulatory power keeping a careful (but generally distant) watch over those business practices.
Very few on 'the left' are full bore socialists, and even fewer are anti-commerce.
