Excuse #3 - It's no use: "The world's dying anyway, so why bother?"
God has promised that he'll be followed by some from every people on the planet. He told Abraham this in Genesis 12 and he showed it to John in Revelation 7:9. From beginning to end we see the relentless work of the Father to gather his wayward kids back home.
If you find in your view of the future the notion that the people of God grow weaker and fewer as history marches on, I contend that the source of your view is a modern and misinformed understanding of where we're headed, and decidedly unbiblical. If we really think things end up with a faithful (very) few finally getting rescued from the onslaught of godless peoples and cultures, it's no wonder we don't rally to global vision and engagement. Huddling and holding on is far smarter.
But that is not the future ahead of us. God told Abraham in Genesis 15:5 his children would be like the stars of the sky and in Revelation 7:9, John said the multitude he saw could not be counted. God's gathering a great harvest. He is not losing. He is not waiting for things to get bad enough to come and get us. He is keeping promises and gathering followers on a grand scale.
I'll be the first to admit that I don't have a sophisticated grasp on various views of "end times." But it is logical that missions vision is squashed by a bleak outlook for the (terrestrial) future of the Church. When we feel as if the Muslims, Maoists, or modernists are taking over, we might naturally be inclined to contract and settle in for a siege, not engage other cultures with boldness and joy.
What do you think? Have you heard this excuse? How would you respond? To what resources would you point me (and others) in order to bolster our understanding of the Church's future?