Were people ever arguing that, or were they arguing that people shouldn't be fired because of their sexual preferences? Are racial minorities being fired because of their opinions about race?
Racial minorities being fired because of their opinion about race - ie, their opinion that they should have the same treatments are whites - was very common as far as I know. To make a different example, the new laws in Russia aren't against "being gay", they are against those who argue for the rights of gays.