It only makes sense from the perspective of screwing third-party repair and then trying to come up with something with plausible deniability. Are people swapping screens frequently enough to justify the extra complexity of keeping calibration data segregated by serial number?

Printer manufacturers have been pulling the same trick with storing (approximations of) ink levels in chips in the cartridge, claiming that it makes it easy for users to swap cartridges and continue to have accurate quantities and in that case there's a little bit more truth to the argument, but not this one.