In the comments there's a link to consumer rights wiki that includes Raspberry Pi's response to this:
> there may be a minor financial gain in buying a part with say a 2GB part, swapping it for an 8GB part of dubious origin, and reselling it as an 8GB device. However, this brings an element of risk to the user - the board hasn't been tested by us - and is a potential support burden for us, with customers complaining of unreliable devices. We therefore remove the commercial incentive by locking devices to their original RAM size.
Frankly, that sounds pretty reasonable to me
I don't agree. They're stopping the owner of the device from using it how they want to based on a theoretical user who purchases a modded device. There may be some small profit to be had in raw material costs but if you factor in the time it takes to pull off a mod like this, and the number of failures I don't think it's a good argument. Even if it was, why not a warning that you can bypass by setting a config in a txt file in the root of the SD? Or even just typing "I agree I won't bother you about this board" or something?
No it does not sound reasonable.
If they want to reduce the support burden they can use serial numbers to track what board has what ram - if they don’t match no support because it’s modified hardware.
Yeah that practice is not unheard of. I can easily imagine having a ready-made device to desolder the original chip out of Raspberry and solder another one, of poor quality and/or counterfeit, and then sell that modded Pi for profit. Heck, remember fake SD cards, USB drives etc.
Therefore I agree with manufacturer's decision.
It's not reasonable. Every company uses a similar "consumer safety" excuse for all its locking down. It's why you can't install apps on iPhones. It's why you can't upgrade the RAM on your laptop. It's why you can't replace your battery when it wears out. It's why your car door won't open if you replace the door handle. It's carefully manipulated PR bullshit in every case.