Luke tells the same parable in a simpler, less militant way. (Luke 14:16-24)  According to Luke, the host invited three friends, but each was predisposed.  One had just bought some land, another five yoke of oxen, and another had just gotten married. Given the particulars, each had a reasonable excuse.  Years ago, a friend of mine put this together in a song and sang it to the tune of "The Beverly Hillbillies."  It went like this:

"I cannot come to the banquet, excuse me, I pray,
I've just bought a field, I must gather my hay;
I hate to miss the party, and I know this sounds dumb,
Pray, Lord, excuse me, I cannot come.

"I cannot come to the banquet, excuse me, dear sir,
I've just bought a cow, and her cream I must stir;
I hate to miss the party, all the food and the fun,
Pray, Lord, excuse me, I cannot come.

"I cannot come to the banquet, excuse me, my Lord,
I've just married a wife, and I gave her my word;
I hate to miss the party, and all that good rum,
Pray, Lord, excuse me, I cannot come.

"I cannot come to the banquet, I'm too busy, you see,
Perhaps another time would be better for me;
I know the table's ready, and I feel like a bum:
Pray, Lord, excuse me, I cannot come!"

Either way, the message is the same: Whatever your excuse, the kingdom must go on.  God is at work reconciling the world to himself and, if we're too busy or, for whatever reason, unwilling to be part of this ministry of reconciliation, God will choose others to do his bidding.