In John 6:30-35, Jesus compared himself to the manna that God provided in the OT:
"So they asked him, "What miraculous sign then will you give that we may see it and believe you? What will you do? 31 Our forefathers ate the manna in the desert; as it is written: 'He gave them bread from heaven to eat.'" 32 Jesus said to them, "I tell you the truth, it is not Moses who has given you the bread from heaven, but it is my Father who gives you the true bread from heaven. 33 For the bread of God is he who comes down from heaven and gives life to the world." 34 "Sir," they said, "from now on give us this bread." 35 Then Jesus declared, "I am the bread of life. He who comes to me will never go hungry, and he who believes in me will never be thirsty."
Because Jesus made this comparison, it seems reasonable to ask if the OT manna was given only to feed a small anointed group of Israelites or all of them. The answer is... all of them. There was no distinction. So why would the bread that represents Christ's body and the wine that represents his blood be only for some anointed group?
In John 6:48-53, Jesus went on to say: "I am the bread of life. 49 Your forefathers ate the manna in the desert, yet they died. 50 But here is the bread that comes down from heaven, which a man may eat and not die. 51 I am the living bread that came down from heaven. If anyone eats of this bread, he will live forever. This bread is my flesh, which I will give for the life of the world." 52 Then the Jews began to argue sharply among themselves, "How can this man give us his flesh to eat?" 53 Jesus said to them, "I tell you the truth, unless you eat the flesh of the Son of Man and drink his blood, you have no life in you."
Doesn't sound like something only for 144,000, does it?
By not partaking, aren't the vast majority of JWs unwittingly testifying against themselves, symbolically saying that they have no part in the bread from heaven and the life it provides? Aren't they saying that the spiritual life within that Christ offers is not within them?