This is one of the most infuriatingly insensitive things you can say to someone struggling with infertility. There's only one worse thing that someone said to me, and I don't even want to repeat that here.
As one who is currently struggling with infertility, going on two years of trying/treatments/etc. I have to disagree with you. The fact of the matter is, if God really wanted us to procreate, he certainly has the power to make that happen. He is, after all, God. We get to pray for it, and want it, and try, and do all that we can, but in the end, "thy will be done". If you choose to take offense, it's all yours.