You've framed the issue in a way that I think obscures a straightforward application of core libertarian principles. Companies are just associations of people

You've framed the issue in a way that I think obscures a straightforward application of core libertarian principles. Companies are just associations of people bound by various contracts, all freely entered into into. So the libertarian belief in freedom of association and freedom of contract lead naturally to the support of any voluntarily formed organization including companies of all types, churches, non-profits, little leagues, partnerships, activist groups, and so on.