Are you allowed to rename your web.config (or app.config) file and have it work just the same? Could I for instance start calling my web.config 'bob.config' and expect it to work? Probably not, because I'm using the Visual Studio tool and it is declaring
how it works. I should work within the tools confines if I want to use the tool for it's numerous benefits.
I know that was a pointed redirection, but for good reason.
The idea to remember here is that NuGet is a tool and it owns that packages directory. Having it configurable may be an option sometime later down the line, but right now it is where the tool stores packages that your code works with. If you would like
to use the tool, please try to understand why it works in the way that it does.
We have many of these discussions and I am strongly in the camp of 'lib' being my directory name for external dependencies. But in the bigger picture, even I have to admit it's very esoteric to ask a tool that has a specific reason for working like it
does to work a different way because it feels wrong when the tool doesn't mold exactly the way we want it to.
That said, I have written a nuget package that will allow you to override that folder name to something else. It is not guaranteed to work and will probably break in the next version. I am not going to link to it here either. It's unsupported functionality
that might cause bad things to happen in the long term. YMMV