pikamaster,
1) I believe the elders cannot understand and they will not
appreciate the concept. To many of them who lived throught the 50s
and the 60s where triads and gangs were ruling the ground, death
penalty was certainly useful. Their question is whether the person
deserves to be hanged. To them death penalty is the only deterant
to gangsterism. What is so immoral about a law that protect the
citizens from gangsters? Putting those convicted in jail for life,
JIAK LIAO BI.
2) "What is so hard about telling our elders, "the Death Penalty is
immoral, we should scrap it from our law" "- you dont tell the
elders, you explain why is this immoral and why it should be
scrapped. you don't give a statement and just expect them to
understand.
"Do they require a uni degree in order to understand the
statement?" - There were few uni degree holders in those days and a
cambridge grade 9 is very lawa liao. Talking to them like that is a
show of disrespect and you are likely to get this kind of answer,
NIN PEH SI BO TAK CE, BEI HIAO, LI BE AN ZHUA? KNN.
In reality, do you talk to elders like that? 
sgdiehard