It's All around the Region, too much Food Waste. Even in everyday meals... 60% Of the Bread is wasted... 30-40% Bigger Portion... And With Time, Ppl give less and less to those in Needs, Nowadays even the poor will be offended to receive a meal...
Anyway, Culture or not, If something is done wrong, then it should be changed. EVen more When a century ago or less, such portion wasn't the norm, Back in The days, My 95 years old Grandfather already called such practice an Heresy... Even though he was from a wealthy family, He told us...That even the Bey wasn't given a full Cow or Baby Camel in the special occasion...
So it's mostly something "Recent" even if Recent in this case is 90-70 years old...
In South Tunisia... You can even get " A full Camel"... Even if it's rare... They do it sometimes...