But it's worse than appliance. Appliance doesn't actively block you from using it for something not listed in instruction manual
PCs are hackable by design. It's a perfectly mainstream thing to build your own PC from parts. Hacking toasters, on the other hand, is not mainstream. Best Buy sells toasters, but not parts for toasters.
I personally wouldnt draw the line between information appliances and computers at whether the manufacturer actively blocks you (as Apple and John Deere do), but rather at some combination of what the intended purpose is, and whether hacking and customization is considered mainstream or fringe.
Hacking toasters and dishwashers and microwaves and refrigerators is possible, but fringe. Hacking cars and houses is mainstream.
Is it? Most PC (or notebook) users buy whichever one is on sale at the store, or they use one provided by their company. This does not strike me as inherently different to how people buy toasters or dishwashers.
Of course, there does exist a niche of people who like building their own PCs, but this does not imply that this is the mainstream case.
I have an espresso machine, and you need to calibrate the pressure, the temperature, clean all the parts regularly (far more than a pod machine), you need to fill the coffee grinds in a way that is distributed so the water runs evenly, you need a coffee grinder that makes less-coarse grinds, etc... its far more work, but the coffee is exactly how I like it.
"Unauthorized Bread" by Cory Doctorow