This should result in the website knowing that the screen is 7" inches (dots-per-inch / dots = inches) across and setting the style for small devices.
Users with NoScript will just have to live without some functionality. I'm sure they are used to that already, since a large fraction of websites use JS for styling. (I use NoScript)
Setting aside the debate about separation of concerns. Yes, it has notable performance and UX implications.
> Users with NoScript will just have to live without some functionality.
Why should we prioritize OP's use case over that of NoScript users?