Why did god choose john to write rev?

John who wrote Revelations is believed to have been a different John than the apostle. The writing between the two books (The Gospel of John and Revelations) is remarkably different than one another. And God did not necessarily choose John to write anything. He very well could have written Revelations all on his own. And Revelations wasn't divinely chosen to be in The Bible, nor were any of the books divinely chosen. The Council of Nicea chose what books would be included in the Bible and Revelations barely made it in by vote! And that's too bad. If it hadn't we wouldn't have kooky people today worried about the end of the world, 666 or even Hell. John was a recluse who lived in a cave and likely had mental problems.