Gov't is not free, it entails a cost. For gov't to invoke a privilege upon anything, ANYTHING, therefore comes at a cost. To assert that invoking any privilege is not a force seems to me as error on the part of the asserting party because said cost requires some manner of force to assure not just payment but then some level of recognition of the privilege authorized and backed by the State.
Also seems to me a basic fundamental operation of economics as the action on the part of one to the benefit of another will require some exchange at the very least for the labor based on time exerted of those who work on behalf of the State. Even a written gov't decree of a purely ceremonial nature invokes a cost upon all taxpayers and said taxes at the end of the day are collected by a means of force standing behind the compulsory commands. At the end of the day, Indiana lawmakers who passed the legislation in question imposed a cost upon everyone in that at the very least their wages for time spent on said bill is a burden on all taxpayers in the manner of an economic force. Any privileged on behalf of some is always paid by all. Even when the privilege is a harm.
Seems to me this issue is as fundamental as understanding the concept of
Positive and Negative Rights. I'm a strong advocate of negative rights while seems to me Indiana engaged in creating Positive Rights. I agree under the negative rights of free association and the right to contract, ANY BUSINESS OWNER has the right to choose with whom they want to do business BUT at the same time this also requires the State to eliminate all market hurdles and walls where for example if the pizza place said "no gay customers", said gay customer could go home, make pizzas out of the kitchen and enter the marketplace in direct competition or even open a business right next door. Zoning laws are the first market barrier to such outcome and therefore the pizza place enjoys a market privilege that protects them from truly open market competition.
As a radical market anarchist, I would crush such market barriers in the first place and then let people discriminate against potential customers all they want as this would now be economic folly IMO.