Does that include your cable company DVR, your PS4, your doorbell, your wifi-enabled refrigerator, your thermostat, and the 50 other devices in your home that contain (or are) computers?

Personal computers are perceived as the last vestige of this sort of freedom in a consumer product, hence the outrage.

None of those other examples are sold with the intention of the user changing the system in a way unexpected by the vendor.

PCs are supposed to be open-ended, and for this you typically pay more for the hardware capability than a product which serves as a gateway into a walled-garden ecosystem (phones, gaming consoles, etc.)

I guess Lenovo should make it clear if the computer is locked or not and maybe offer an upgrade option to get it unlocked.

Yes, of course. Why wouldn't I include them?

Any cpu in my household is mine (presumably.) I don't care what peripherals it has, it's just a computer.

From my POV all those devices are just computers with various peripherals. I don't see any way in which attaching a specific peripheral changes the universal nature of the cpu.

Worse, it's like trying to control where you can drive it.