1Corinthians 11:25-26:
“In the same way, after supper he took the cup, saying, “This cup is the new covenant in my blood; do this, whenever you drink it, in remembrance of me.” For whenever you eat this bread and drink this cup, you proclaim the Lord’s death UNTIL HE COMES.” (emphasis mine)
The JWs teach that Jesus Christ returned in 1914 when his kingdom officially took power and he began active rulership toward all the world. So the JWs should have ceased commemorating the memorial of Christ’s death since according to their theology, Jesus returned in 1914.
http://mmoutreachinc.com/jehovahs_witnesses/1914.html
*****What is Truth? (1932) p.48*****
“The prophecy of the Bible, fully supported by the physical facts in fulfilment thereof, shows that the SECOND COMING of Christ dates from the fall of the year 1914.” (emphasis mine)
*****Watchtower 1933 Dec 1 p.362*****
“The year 1914, therefore, marks the SECOND COMING of the Lord Jesus Christ, the King of glory.” (emphasis mine)
http://www.jwfacts.com/watchtower/failed-1914-predictions.php
So since Jesus Christ already came in 1914, no need to continue commemorating the memorial of his death.