"Sarah Palin's views and values in NO WAY represent us as American women. We ask that our song 'Barracuda' no longer be used to promote her image. The song 'Barracuda' was written in the late 70s as a scathing rant against the soulless, corporate nature of the music business, particularly for women. (The 'barracuda' represented the business.) While Heart did not and would not authorize the use of their song at the RNC, there's irony in Republican strategists' choice to make use of it there."
Ann Wilson revealed in interviews that the song was about Heart's anger towards Mushroom Records attempted publicity stunt involving sisters Ann and Nancy and a made up lesbian affair. The song particularly focuses on Ann's rage towards a fan who came up to her after a concert asking how her "lover" was. She initially thought he was talking about her then boyfriend, band member Michael Fisher. After he revealed he was talking about her sister Nancy Wilson, Ann became angry and went back to her hotel room to write the song.
So it's quite literally a song written in anger at deliberate corporate deception.
So, on further reflection: Not so much ironic, more an act of astonishing, though inadvertant honesty.