Planned obsolescence seems better than unplanned obsolescence? If your uniformed consumer were informed of the lifetime of the product they buy, they might not be conned into buying things your informed consumer is aware of and avoids.
That's good because, as of current, when the population of uninformed consumers drive market forces, they often push out the options informed consumers would choose or at the very least, create trends towards the uninformed bias purchases that force informed consumers to start choosing the same options as well or drive up prices for the products informed consumers often buy due to lessened demand.
You know, when a bunch of people decide we'll let businesses stop producing devices we can repair or put out rent-seeking price structures and the rest of people are forced to use those options, all because of large scale manipulation of consumer perception. Then we end up with markets filled with garbage with fluffy profit margins for their owners... Then again, cigarettes still have a large market somehow, so maybe we're out of luck either way.
It also doesn't mean anyone will actually support it. I have plenty of devices which you can flash your own OS on but eventually the hobby community gets bored and no one is left supporting it.
You also have the problem of getting every user of the product to flash some custom OS on their hard drive when they likely don't know how or don't know why they should care.
Instead, along the same lines as right to repair, such products should be required to release the firmware source code.