No, I didn't know Hendrix. But since I've been invited to judge for myself I would suggest that Hendrix was being flippant in the above interview and that his peace sign is the real message. His pacifist leanings are perhaps more clearly expressed later in "Machine Gun" (Band of Gypsies).
And I would bet my Telecaster, my Les Paul AND my Mesa Boogie that I'm not the only one who heard protest (as well as beauty and genius) in Star Spangled Banner! But of course, instrumental music has always been open to interpretation.