"For I received from the Lord that which I also delivered to you: that the Lord Jesus on the same night in which He was betrayed took bread; and when He had given thanks, He broke it and said, 'Take, eat; this is My body which is broken for you; do this in remembrance of Me.' In the same manner He also took the cup after supper, saying, 'This cup is the new covenant in My blood. This do, as often as you drink it, in remembrance of me.' For as often as you eat this bread and drink this cup, you proclaim the Lord's death till He comes" (I Corinthians 11:23- 26).
If your boss told you, "Go do some work." - would you just go and observe others doing work? Of course not! So, why do Jehovah's Witnesses not obey this simple command of accepting the blood and body of Christ to seal them into the New Covenant? I have always found this very odd.
Jesus did not say, "Observe this in remembrance of me. Just watch, don't partake!"