No one hearing it was symbolic would have left. Even in previous chapters he layed out symbolic stuff no one leaves.
The opposition sounds just like you did:
52Then the Jews
began to argue with one another, saying, “How can this man give us
His flesh to eat?”
This is where most disciples leave Jesus. And you think its over mere symbolic issue that broke the camel's back?
Even in your own churches when have you ever heard anyone say......symbolic....whoa thats where I draw the line!.
No one has any problem with Jesus being symbolic he has done it before.
Just a chapter before:
31Meanwhile the disciples were urging Him, saying, “Rabbi, eat.”
32But He said to them, “I have food to eat that you do not know about.”
33So the disciples were saying to one another, “No one brought Him
anything to eat, did he?”
34Jesus said to them, “My food is to do the will of Him who sent Me and to accomplish His work.
No disciple threw a fit. Jesus explains his symbolism.
But in John 6, oh no......
52Then the Jews
began to argue with one another, saying, “How can this man give us
His flesh to eat?”
53So Jesus said to them, “Truly, truly, I say to you, unless you eat the flesh of the Son of Man and drink His blood, you have no life in yourselves.
54“He who eats My flesh and drinks My blood has eternal life, and I will raise him up on the last day.
55“For My flesh is true food, and My blood is true drink.
For my flesh is TRUE FOOD and MY BLOOD IS TRUE DRINK.
"He is not literally saying "eat my flesh" we are not cannibals."
Literally saying, in fact the charge of christian being cannibals was common.
ST JUSTIN MARTYR
"This food we call the Eucharist, of which no one is allowed to partake except one who believes that the things we teach are true, and has received the washing for forgiveness of sins and for rebirth, and who lives as Christ handed down to us. For we do not receive these things as common bread or common drink; but as Jesus Christ our Savior being incarnate by God's Word took flesh and blood for our salvation, so also we have been taught that the food consecrated by the Word of prayer which comes from him, from which our flesh and blood are nourished by transformation, is the flesh and blood of that incarnate Jesus."
"First Apology", Ch. 66, inter A.D. 148-155.
"God has therefore announced in advance that all the sacrifices offered in His name, which Jesus Christ offered, that is, in the Eucharist of the Bread and of the Chalice, which are offered by us Christians in every part of the world, are pleasing to Him."
"Dialogue with Trypho", Ch. 117, circa 130-160 A.D.
Moreover, as I said before, concerning the sacrifices which you at that time offered, God speaks through Malachias, one of the twelve, as follows: 'I have no pleasure in you, says the Lord; and I will not accept your sacrifices from your hands; for from the rising of the sun until its setting, my name has been glorified among the gentiles; and in every place incense is offered to my name, and a clean offering: for great is my name among the gentiles, says the Lord; but you profane it.' It is of the sacrifices offered to Him in every place by us, the gentiles, that is, of the Bread of the Eucharist and likewise of the cup of the Eucharist, that He speaks at that time; and He says that we glorify His name, while you profane it."
-"Dialogue with Trypho", [41: 8-10]
Justin points out the God given prophesy:
11“For from the rising of the sun even to its setting, My name
will be great among the nations, and in every place incense is going to be offered to My name, and a grain offering
that is pure; for My name
will be great among the nations,” says the LORD of hosts.
Where is your incense, grain offering and altar? We got you covered, we do this all day long everyday. There is Eucharist being celebrated somewhere all the time.