People have often wondered why she did not do it for the sake of her sons, Michael Meeropol said.
Because she was a committed communist, and she cared more about becoming a martyr for the Cause than she did for her children.
Julius and Ethel were committed communists, conceived of themselves as soldiers in the Cause, and followed the Party's orders to the end. It would be interesting to know what they privately thought, and it is still (barely) possible that some ex-communist will surface with relevant information.
History does throw up interesting questions. We have here spies for Uncle Joe (Ethel was fully complicit in what Julius was doing, even if she -- a homemaker -- didn't personally steal the secrets), who had the courage to die for their beliefs. They belong on the same moral plane as the SS men who died in the last ditch for Hitler.