We should respect people's faith. In the case of Roman Catholicism, it developed over a very long period of time. There had to beliefs already circulating for this to become a doctrine. If this is so important, Jesus should have clearly stated whether he was the son of man, son of God, and his messianic consciousness. When he presided over the Last Supper, he should have told us expressly. Creeds never sound elegant to me. All we know the words that the gospel writers impute to him.
Since scripture is not express, we are all guessing. My father and most Witnesses were rabidly antiCatholic when I grew up. A certain fury was reserved for Catholic belief when logically, it should have extended to Protestant beliefs, too. I was in preschool when I was first told how utterly disgusting feeding on a cadaver is. Now that I am much older and exposed to the world, I see beauty in the doctrine. I am neither for it nor against it. It does seem that important to me.
I just realized I don't know what the Witnesses teach about memorial emblems. Are they tokens? Since they don't believe Jesus is God, it places Christ being present much less important. Transubstantiation harkens to a faith that God sustains is, that we embrace God, receive grace. I no longer see it as a cannibalistic act. He is God, according to almost all Christians. Christ does not have a fleshly body in heaven. The Eucharist is a visible sign of his Presence. Many things may not sound completely logical to me but I view my faith as tradition handed down from generation after generation.
I don't know what Luther or Calvin believed. The Eastern view is important, too. I know there is a slight difference between East and West.