I don't see how people are saying Bush43 is worse than Harding and Hoover. Those two go on their own plateau--it's that that the people lving through Bush tend to exaggerate his ineptitude as they have experience it themselves and not just read some articles on the internet.
Harding deserves some credit for initiating the only naval arms limitation treaty of its time. Hoover had some bad luck to be in the wrong place at the wrong time, but he really could have done more to ease the Depression. Bush43 didn't just have bad luck, nor did he do the world any good at all.