Protestants don't reject the Lord's Supper Communion service and "Eucharist" means thanksgiving. Most churches regularly schedule this remembrance ceremony. What is rejected is the Roman Catholic interpretation of what Jesus and Paul actually said. We believe Jesus' body was broken and his blood was shed to make propitiation for our sins and the act of partaking of the Communion bread and wine is an outward testimony that we have ALREADY received Jesus as our savior by faith. We don't look to this "sacrament" as an avenue to receiving a portion of grace needed to BE saved since we ARE saved when we first believed on Christ and were born again as children of God. So, just like Paul said Jesus said, we do this in remembrance of Him and testify of his death for us until He comes again in glory. Why do so many Catholics reject what Paul said?
The next few verses from Corinthians also point to its sacramental nature:
27Therefore whoever eats the bread or drinks the cup of the Lord in an unworthy manner, shall be guilty of the body and the blood of the Lord.28But a man must examine himself, and in so doing he is to eat of the bread and drink of the cup.29For he who eats and drinks, eats and drinks judgment to himself if he does not judge the body rightly.30For this reason many among you are weak and sick, and a number sleep.31But if we judged ourselves rightly, we would not be judged.32But when we are judged, we are disciplined by the Lord so that we will not be condemned along with the world.
33So then, my brethren, when you come together to eat, wait for one another.34If anyone is hungry, let him eat at home, so that you will not come together for judgment. The remaining matters I will arrange when I come.