Presumption of innocence and proven beyond all reasonable doubt is the bar that has to be met in order to put someone in prison.

However, people are completely entitled to decide to shun someone or not do business with them based on mere suspicion or some arbitrary subjective standards (with certain narrow exceptions e.g. discrimination of protected classes) - "freedom of association" is the default condition and a key freedom, people and companies are free to choose with whom they want to (not) associate.

Freedom of association is not absolute, some limitations can be justified (the discrimination laws are a good example) but there does need to be a solid justification and specific serious harm prevented if you want to argue that someone or some organization needs to be denied that freedom of association.