[brendoelfrendo]

I think you're right, but I think the mental model of the average computer user does not assume that the computer is predictable and repeatable. Most conventional software will behave in the same way, every time, if you perform the same operations, but I think the average user views computers as black boxes that are fundamentally unpredictable. Complex tasks will have a learning curve, and there may be multiple paths that arrive at the same end result; these paths can also be changed at the will of the person who made the software, which is probably something the average user is used to in our days of auto-updating app stores, OS upgrades, and cloud services. The computer is still deterministic, but it doesn't feel that way when the interface is constantly shifting and all of the "complicated" bits that expose what the software is actually doing are obfuscated or removed (for user convenience, of course).