Difference is I don’t own a company, but you are more than welcome to have a soured opinion of the company I work for for employing me based in whatever political beliefs I hold. How is this any different than boycotting JKR for her right wing TERF donations?

Me giving Mullvad money will directly put money in this co-founder’s pocket to give to facists, not just as an employee but as a stake holder in that company. No, he can’t be fired, and I would also not like to be fired for my political beliefs, but the population is absolute free to chose not to spend money at establishments that hosts those views.

I think you can apply Occam’s razor here. Do people just not want to fund someone with express interest in racist/racist/nazist ideology like with JKR, Musk, Trump etc. or is there a conspiracy that 3-letter agencies are sour they can’t crack Mullvad and so want people to use other services?