Originally Posted by
Central Scrutinizer
The CG position is also relevant here.
It's possible that an empty aircraft is at the limit of the acceptable CG range. If the designer were to "allow" an even lower weight, it may have to expand the acceptable CG range and doing so has all sorts of cascading consequences.
Fokker 50 needed a few hundred kilos in the back on empty flights. Also, don't see a lot of Zappa fans your age...