Historian Mark Tauger points out that the peasants shot themselves in the foot in addition to having a natural famine as well as the commissioners (who weren't Jewish but ethnic Ukrainians) being dicks. This link contains his essays showing this. However a daily beast article points this out:
Not surprisingly, Blinova makes no mention of that—or of reports on the famine by British journalists Gareth Jones and Malcolm Muggeridge two years before Walker’s fictions. (Jones, who coined the term “man-made famine,” was barred from re-entering the Soviet Union in retaliation; in 1935, he was murdered by bandits while traveling in China, in what may have been a hit organized by Stalin’s secret police.) Nor does she mention accounts by Russian Jewish writers Vasily Grossman and Lev Kopelev, who could hardly be suspected of pro-Nazi sympathies. And, of course, she does not say a word about declassified documents such as government decrees imposing draconian punitive measures on villages that failed to meet grain production quotas—including confiscation of all food and a complete cutoff of supplies.
I should point out this was happening in Russia as well...so should we really call this an ethnic genocide?