It may well so be it's an alleged fraud and Venezuela can and has dealt with that as they see fit. That still doesn't negate that gesture as presented on behalf of the American people as anything other than a humanitarian effort to help, even if they turn it down Americans can feel better that they tried. I can see your point on the sanctions not helping the situation but on the other hand from what I have seen from those posting here on this platform who live there and describe the situation it really wouldn't make much sense to avail to Maduro the ability to further buy more arms to use against those who oppose him, continue to allow himself to enrich the lives of others while simultaneously and willingly let those who oppose him starve. But that is just my opinion and I don't hold much sway over our government or over other countries governments either way the debate flows out.
Americans are pretty worn out though on the invasion for oil warring, that's why I think you see there has been no movement against Venezuela militarily. I think that's why you don't see more people concerned with the pull out in Syria, even though the US military is standing on the oil grounds the war was fought by those internally outside of ridding the country of ISIS fighters that they were engaged with, from the public's perspective it was internal, the opposition lost, it's time to move on now that ISIS has been defeated. People are good with that, it's sad for those who will have to live under what they consider oppression but outside of genocide being committed it's not our fight.