

2FA should probably be enforced for the process of publishing packages
The most successful recent attacks haven’t relied on stolen user credentials, so this point is kind of moot. API tokens are way easier to obtain and use. Typo squatting and phishing are more effective, and attackers generally don’t need to bypass 2FA.
Linux distros usually rip out build scripts and build systems in order to replace them with their own, but this also further limits the code you have to audit.
Linux users who routinely download and compile src packages is a minuscule attack vector. Most users download binaries, so this point isn’t true either.
And look, I agree that MFA should be mandatory everywhere, and sandboxing is great, but the truth is that the JS ecosystem is chock full of lazy and sloppy devs. That’s just how it has been for the longest time, and no amount of security measures targeting them specifically is going to fix the current state of affairs, because as soon as one is implemented, someone will find it too cumbersome and will find a way to override it. The whole ecosystem needs adult supervision.
But honestly, I believe that JS in the backend has been a massive mistake and we all should abandon it as soon as possible. There are plenty of better languages and ecosystems out there, no need to keep self inflicting this kind of pain.

They know. They just don’t care.