I guess it just seems haughty and almost arrogant to say "no, this isn't good enough for me because I have something similar and this is different" when instead it could be treated as something totally different, which really it is, not something that is taking away from or disputing the transubstantiation in Catholic Communion. It's not like the Lutheran Church is making a sacrilege of Communion by doing it the way they do, they're not even opposing any beliefs of the Catholic Church. Their Communion is just not as special, it's not as intimate. But the Catholic Church has nothing wrong with symbols, and that's all that their Communion is, so there should be nothing wrong with it. Because their Communion is merely symbolic and therefore not nearly as intimate, it is definitely no replacement and should never be thought of as such, but I don't understand what is wrong with participating.
(The original questioner has kept the conversation going...)
Q: So the big problem with it then is that it signifies that we are all united as one, even though we aren't? And that's what makes it superficial? That doesn't really make sense to me. "For just as the body is one and has many members, and all the members of the body, though many, are one body, so it is with Christ. For in the one spirit we were all baptized into one body- Jews or Greeks, slaves of free- and we were all made to drink of one spirit." (1 Corinthians 12: 12-13). Christ came to die for all of us, not just Catholics, so why do we separate ourselves from other Churches? I think the part I don't understand is what you mean when you say "While our hope is to one day be in communion with all the protestants, we aren't right now". To me it seems like, just as the verse says, we are all one body in Christ, we are all saved by grace just the same, and though we are different, we are all united. St Paul repeats this idea when he says, "For as in one body we have many members, and not all the members have the same function, so we, who are many, are one body in Christ, and individually we are members of one another." (Romans 12: 4-5). If we are all united as one body in Christ, why do we reject this symbol of unity?