A man has no greater love than to lay his life down for his friends, but in the שמי tradition, only circumcised males are allowed to serve their society in such a way. In this tradition therefore, circumcision is the sign of the deepest true love for preserving a peaceful society. When a circumcised male lays his life down for his people it is not a tragedy because this is what he was born for, thus such men are praised and exalted. But when a non-circumcised person has to do this it is mourned as a tragedy and failure in the system that one trained for this destiny was not available.
Unlike Beth Hillel, שמי has actually institutionalised the idea that sacrifice of one's life for the good of the people may in certain circumstances be acceptable but it is volunteer only and uncircumcised people are never hoped to take this burden upon their shoulders.
see also Sanhedrin 59b