On the one hand, a repair technician doing <i>anything</i> with <i>anything</i> other than what they're supposed to be fixing is wrong. On the other hand, boards don't last forever, and if you have a rare one for which no ROM has ever been dumped, and you refuse to dump yours, you're a selfish jerk.
Although I strongly believe in preservation I also understand that some things will be lost forever. Although we try to preserve as much as possible we cannot preserve it all. As long as we preserve the majority of software/hardware does it really matter if some things get lost?