Earlier quoted context omitted.
They can produce a warning on unused stuff, instead of an error and not force this idea on everyone, especially considering they have zero proof on this idea. Also, every large project starts from a small one.
What's the argument for allowing un-used imports? I've never run into a case where I wished I had imported something but didn't want to use it If you're looking at future code, you can accomplish that by commenting out the import. But I've never run into the situation where writing future code has been good, or where I wouldn't have remembered to import the package I needed when I wrote that code. If you really need…
I personally find it annoying because I compile often. In my workflow I write code for a few minutes then compile it and run some quick tests or even run it through the debugger to make sure everything is working the way I expect. If everything checks out I start on the next bit. I may be adding a feature that I know in advance will use libraries xxx, yyy, and zzz. The natural thing to do is to add those imports when I open the source files that will use them, then get to work implementing the feature.
Another useful reason is to import a library just to make sure it's installed correctly, before writing the code that uses it, although that's less common.