Hm.
Hypothetical: if you modify the software in a Tesla, and your modification allows a hacker to remote control it, and this power is used to commit vehicular homicide, how much of the burden of responsibility do you have?
I’m not a lawyer, so while I can throw out phrases like “endangering others through negligence”, I don’t know what the threshold is or even if that’s the right concept in this case.
With regards to game consoles, I tend to agree with you — no good reason for them to be allowed to prevent side-loading.
With regards to phones however, I explicitly want the devices heavily locked down by law, to the extent that other people should not be allowed to put random software on them. This is because they are powerful sensor packages that almost everyone carries almost all the time, so the mere possibility of malware turning them into blackmail spy boxes is a problem for all of society — everyone, given what I’ve heard about “three felonies per day” [0] — and not just the person who installs the dodgy app.
I say this despite not liking that the action of American cultural hegemony in the App Store means those stores have a bigger problem with nipples than with violence.
And likewise, I have a problem with the law that requires me (a British citizen working in Germany) to keep the U.S. government informed about my app’s use of encryption in case I “export” something they can’t break, which is insane in my opinion.
Security is important and app stores help, but trust can be chained and delegated, and it is possible to have alternative App Stores which Apple/Google audit for security.
[0] https://kottke.org/13/06/you-commit-three-felonies-a-day