I don't really understand how this is an issue. The raspberry pi/raspian distro is made primarily for education, so making it easier to install VSCode which is a popular tool (and also one of the recommended tools for developing for the new Raspberry Pi Pico) is a good thing. It's not like VSCode is being forcibly installed on all raspberry pi's, just because the repo is in the source lists doesn't mean you have to install anything from it.