I can understand how Billie Holiday’s “Strange Fruit” could be seen in conjunction with low hanging fruit, but I believe it’s a bit of a stretch to see the term low hanging fruit as nothing more than fruit that is hanging from branches low enough to pick them from the ground.
Where the phrase is used outside the US, I agree with Teed. But within the US I can understand how this can be seen as grossly offensive, therefore the use of this phrase should be carefully considered in the presence of African Americans. If in any doubt don’t use it.