One purpose of the U.S. Constitution is to limit the control the government has over its citizens.
This has, within the last 75 years, been reduced or ignored by Supreme Court rulings and the general sentiment of Congress. It would seem that the government always wants more authority to discipline the citizenry.
The Mississippi religious freedom law is not basically about protecting religion but rather about limiting government control over its people. Religion is the issue that brought this currently to light.
It is clear that government should not discriminate against any of its citizens. Should this same prohibition be applied to those citizens? Is it OK to say “I will not hire an illegal immigrant” but not to say “I will not serve a LGBT person”?
The citizen should have a right to conduct his business as he pleases. If this brings societal wrath down on him and his business fails, so be it. But for the government to say, “We will control who you will serve” is against the reasons this country was founded.