I don't recollect Kumbaya in the UK ever having the hint of despair, possibly even the despair that leads to revolution, that the familiarity with Gullah might have given it in the USA.

It just sounded kind of twee, and we were not taking our hope from religion in the 60s (except in a Timothy Leary sort of way). From the UK perspective of the Aldermaston march the hint of uprising in "We shall overcome" spoke in a way that was easier to relate to.