You don't know much about Calvinism as you have admitted. That is sad. Before rejecting it, you should at least understand it.
Armenianism says the same thing regarding John 3:16! God so love the world that he gave...so that those who receive....shall not..... but have........!
The difference is that Calvinism stresses God giving the gift, where Armenianism stresses the receiving of the gift! It may be better to give than to receive, but oh my, failure to receive has tremendous ramifications. Only God can give the Gift of Life, but only man can receive the Gift of life. God gave the gift to none other than man! Now, theoretically, I could give you 1 million dollars, but if you fail to receive it, it is not yours! The Giving is of great significance, but the receiving is of equal significance to the receiver.
Both the giver and the receiver are parties to the transaction, both must participate in order to complete the transaction
God gave his gift to the whole world, but only those individuals of the world who participate, and receive that Glorious Gift actually possess it. The rest of the world doesn't seem to know the gift was given.
You would say, "that proves Calvinism correct because those who receive are pre-ordained to receive it". Armenianism says that God already knows those who will make the choice to receive it. For eternal God, that is no big deal! To him, what has been is as fresh as what is, and there are no surprizes to come. He is omniscient, knowing what was, is, and is to come; all terms relative to His creation, for there is no time in eternity.
The Lambs book of Life was not sealed before the foundation of the world, it remains open and many names are added daily along with those who were written before the foundation of the world. Those added names are written with Jesus' blood, and they are "the whosoevers" of the world who believe in Jesus.
Calvinism says that the Gospel message is for "the elect". Armenianism says the Gospel message is to "anyone who will hear and believe".
God says that it is his desire that none should persish but have everlasting life. He did not say that none of the elect should perish..... It is God's desire that all who ever lived would choose Him over the father of lies. But alas, we know that has not happened, because the illustration of the lake of fire implies a big lake, not a backyard pond.