I don't think that opinion is so unpopular as you imagine, it's technically true. However, the global effect of such commercial decisions can effectively add up to censorship. We should pay attention _before_ that happens, because afterwards it can be too late to get it changed without momentous cultural shifts.
The behaviour of the major cinema chains in the US has the _effect_ of distorting the use of movie ratings and making a supposedly private commercial outfit into effectively a government censor. And they seem, if anything, overjoyed to be granted this power.
Or another example, small US states are legally permitted to buy any school textbooks they like, but in practice the textbook makers are most responsive to the rules laid down by the most populous states. If those states don't want a particular element of Geography, History or Mathematics taught, it does not get taught by textbooks even in the states that don't have such rules.