You start off by saying "The user might use his control to make his computer less secure" which is true. But just two sentences later you claim "users choose to not upgrade their insecure software" which is obviously false. They might but the might not.
I could argue the same way and claim that removing user choice might make the computer less secure e.g. by forcing updates to an insecure version, installing backdoors etc. In the real world, this is exactly what happens. Therefore removing user control makes computers less secure. Now do you agree or do you think that my argument is deeply flawed?
I don't see how your argument works. You seem to be saying that user control automatically leads to less security which is obviously false. Maybe you are conflating groups with individuals. If an individual has control then by definition he can chose to be more secure or less secure by his actions e.g that individual may chose to perform updates asap and stay away from suspicious downloads. He can also chose to do the opposite of these things and be less secure but there is obviously no direct implication either way. But underlying this is a one-dimensional view of security, consider more complex scenarios where users are forced to use a single software to perform a task. If that software is insecure then 100% of users are vulnerable whereas if there are a diverse range of programs the users are more resilient to attacks.
I could argue the same way and claim that removing user choice might make the computer less secure e.g. by forcing updates to an insecure version, installing backdoors etc. In the real world, this is exactly what happens. Therefore removing user control makes computers less secure. Now do you agree or do you think that my argument is deeply flawed?