I am quite surprised by the lack of appreciation by some members here - including some frequent flyers - of the concept of limiting liability. Anyone involved in business should be familiar with this concept.
Now one could certainly argue that the Montreal Convention limits are too low, and/or that airlines should perhaps do more to highlight the limits during booking, but I don't think it is realistic to expect them to accept unlimited liability for items carried.
If you own very high value goods you really should be checking you are comfortable with your coverage and limits, whether taking such items to the dry cleaners, sending post, flying, etc...