>I should also think that libertarians should be in support of private people deciding not to support companies or people that support causes they disagree with

As a liberal, not a libertarian, I would say that's a bit reductive.

People should have the right to express their political beliefs. The fear of cancellation and potentially losing their job etc isn't conducive to freedom of thought. Yes you individually may not agree and may choose not to support them, but here we have people actively calling on others not to support them, and condemning those who would choose to carry on engaging.

It's very divisive, 'you are either with us or against us'. That is far from any kind of liberty.