What was the Smoot-Hawley Tariff Act of 1930 if not government intervention? As the article states the effects of the tariff and government regulations on banks which created banks to have bad policies caused the Great Depression. To a certain extent banks must engage in speculation. If they didn't they wouldn't make any loans.
A couple of opinion interjections:
1) Yes, Smoot-Hawley was government intervention after the fact, as was were the creation of the FDIC, NCUA, and the Economic Stimulus Act of 2008. Not all government intervention is a bad thing.
2) The assertion that "government regulations on banks which [caused] banks to have bad policies" - well, that is such an counterintuitive assertion that it will require more explanation. Let me put a bookmark in here, I'll label it "bunk" for the meantime... (not yours, theirs). It's like the canard that "Clinton caused the Great Recession," which is demonstrably false. Banks make bad decisions. Usually, like other bad financial decisions, it is based upon greed and/or corruption. The GD was no exception.