It is not even boycot for political reason (and conservatives do those all the time). It is literally just conservative cold business decision of "I don't trust that guy". This concept of freedom where others are mandated to do business or not do business or listen someone is super odd.

Advertisers have free speech right to not do business with Twitter. They have right to not do business with me too. Just like Musk has right to fire people from his company.

Free speech means also freedom to criticize twitter or disassociate from it when you think it affects your business.a