I agree with your point to a certain degree. I think we should be willing to try bad/risky ideas occasionally if just to remind ourselves why they are bad. However:
1. It can take years to make something and seconds to break it. These changes are so drastic and damaging that we may permanently set our economy back decades, especially when if other countries no longer trust us.
2. It puts a lot of faith in politicians to admit mistakes. The disastrous trade policies of the 1930s were never gotten rid of until after they led to WWII.
It's like touching the stovetop after already having been burned, why would you do it? It's not like the tariffs promised were well thought out / structured to actually boost FDI and domestic manufacturing.