How do YOU know that?
God is the same, Yesterday, Today, AND Forever. That means that if He granted visions in the past, he can do it now if He wants.
If God wishes to reveal something to us dummies, who am I to rebuke God?
Because the bible makes the case for itself being the final revelation from God. It's time for you people to think about the ramifications of your beliefs. IF the bible is not the final and complete word of God for us, then the bible is lying about itself. If the bible is lying about itself in one area, then we cannot trust it at all, which means we have no reason to be here as Christians.
To put it another way, Who is to say what is actually a word from God and what is not, unless it is in the Bible ? God is not the author of confusion, but person X can just as easily say that God "told me" to divorce my wife, contrary to what the bible says. Who's to say he's wrong ? It lessens the reliability and authority of scripture.