That a 404, 301, and 500 being generated by the API vs the web server are very different events and it’s hard to think of where “various tools” handling them the same is the right choice? What examples do you have where it’s the right choice?
I forget exactly what the scenario was but the request was not being sent with credentials so a 401 was returned, which immediately prompted a retry with the credentials. I'd probably agree that this is covering up an issue that should be fixed.
So in this case you're relying on a specific client's decision more than you're relying on universal interface.