Why did they think the great depression Hoovers fault?

Answer 1

Mostly because it happened "on his watch" as the saying goes, and he had made the campaign speech about "A chicken in every pot, two cars in every garage, and prosperity is just around the corner". Also, once the market crashed and the depression hit, Hoover did little to really help the American people, insisting that business would work out out the problems soon enough. All that said, it still appears, historically, that the lions share of the blame for the market crash and Depression should be laid at the feet of Calvin Coolidge, rather than Hoover. The market crash and Depression were a result of an orgy of financial jerry-rigging that went on during Coolidge's administration, which he turned a blind eye to by saying, repeatedly: "The business of America is Business".

Answer 2

Many people believed that President Herbert Hoover was responsible for the Great Depression because they felt that his policies, such as high tariffs and limited government intervention, exacerbated the economic downturn. Furthermore, Hoover's belief in voluntary cooperation instead of direct government aid was seen as insufficient in addressing the widespread unemployment and poverty during the depression. Ultimately, public dissatisfaction with his handling of the crisis led to the perception that Hoover was At Fault.