I believe this is not the strongest argument to make. There are plenty of products that do have legitimate safety or other regulatory concerns, where there is a good reason to prevent someone who doesn't know what they're doing from meddling.

However, the relevant point is whether they know what they're doing, not whether they have the blessing of the manufacturer. I tend to think that saying devices in regulated fields can only be modified by someone suitably qualified and experienced is reasonable, but that in such a case the owner and the qualified person modifying the owner's device should not be artificially constrained through things like unnecessary regulation or intellectual property laws.

There are also ethical and economic questions around supporting fair competition in markets for replacement parts from alternative sources or examination and modification of source code in the case of software. On the one hand, we do have IP laws to encourage creators to create and to protect them from someone ripping off all their hard work the day after their multi-year, multi-billion R&D exercise finishes. On the other hand, those laws aren't supposed to be there so an inventor can sell an artificially crippled product and then charge extortionate rates for servicing , replacement parts or essential updates to correct defects in the original product. There's a lot of room for progress in this kind of area today, IMHO.