Yeah, Open Source / Open Hardware in IoT is a step back in the direction of how things always were and how they are supposed to be - you buy the device, you own it. People understand that. They expect their washing machines and microwave ovens to work until the hardware itself breaks (let's forget for a moment about the sick practice of planned obsolescence). They expect to be able to repair them or find a third party that can.
People don't have to understand "open source". They will understand the concept of "works until hardware dies", or "can be taken to a repairman for fixing", or "I can go to a mall and buy an extension from some random vendor and it will work".
This is doubtful. Nobody buys a new furnace when it has a problem. Ovens, fridges, and dishwashers are all generally far cheaper to repair with a local repairman than replace.
A lot of house or condo sales now come with "home warranties", where a flat fee guarantees your appliances for a year, and repairs only cost a $100 deductible.
Computers in most cases, even, are now appliance-like. They get replaced less often, and it's often more affordable to repair them than replace them.
People don't have to understand "open source". They will understand the concept of "works until hardware dies", or "can be taken to a repairman for fixing", or "I can go to a mall and buy an extension from some random vendor and it will work".