The ones defending her firing are the ones that demand personal responsibility.  She's welcome to make vulgar gestures toward President Trump all day long, every day until January 20, 2025 if she wants, but her employer does not have to keep her on the payroll if her actions bring upon them ill repute.  Would you say the same if she were running around with a Nazi flag and shouting white supremacist slogans on a DC street corner?  She has that "right," but should still be fired.