First of all - love the name. Second - full disclosure - I’m a Protestant (Reformed flavor). Third, to the OP, I would say that if one feels that a Protestant - or anyone for that matter - is trying to bully you into a “Bible study” by accusing you of having a “hard heart”, it’s not a Bible study at all. Christians study the Bible together because wherever 2 or 3 are gathered in our King’s name, he promises to be there. Our study should be focused on Him first, and loving each other (our neighbors) second. Anything else reeks of pride. I am sorry that this Protestant is behaving this way and on behalf of all Protestants ask for your forgiveness. Now on to the topic at hand.
I’d be a bit careful with the idiomatic argument - or at least using it in a vacuum. In the Sermon on the Mount (Matt 5:30), Jesus said, “If your right hand causes you to sin, cut it off and throw it away…” As far as we know, all the disciples had both hands (and eyes), no? And besides, the theological argument that Protestants (especially Reformed Protestants) have with transubstantiation is around the concept of continual sacrifice. It’s a long story, but the way simple answer is that we try to hold John 6 in tension with Hebrews 10 (kairos and chronos time notwithstanding).
Having said that, I think we Protestants have completely thrown the baby out with the bathwater when it comes to liturgy in general and the Eucharist in particular. I mean, cheese and rice, we corporately confess our loyalty to the United States (which is a good thing) way more than we corporately profess our faith in Christ (you guys say the Nicene Creed at every Mass). We celebrate the Eucharist way to infrequently, and when we do, we don’t take it nearly seriously enough (as Paul directs us in 1 Corinthians).
But I digress. If I were a Catholic, I would tell a Protestant that I take the Lord’s Supper very, very seriously as directed by Christ himself and seconded St. Paul. I take Christ - my King, my Savior and my friend, at his word that, through the eyes of faith, he is actually physically present in the Eucharist. Every time I eat his body and drink his blood, I’m reminded of and sustained by the incredible sacrifice he made for me. By his grace and through the sacraments I come to know more and more who I am, and (more importantly) whose I am.
I’m a Reformed Protestant and will always be one. But I’m also a Reformed Protestant who is very, very thankful for and cognizant of the defense of orthodoxy that the Roman Catholic church has provided all of us for thousands of years. My continual hope and prayer is that one day, sooner rather than later, we can celebrate our shared love for our great King and Savior together over His table.