It makes no sense. Those types are just scared of the possibilities of a God actually existing otherwise there would be no reason to make such a quick and absolute answer of this just being it.
This is simply fallacious. To put it as honestly but bluntly as possible: there is no space being to be scared of in the first place. It isn't about fear, but about absolute lack of evidence in its favour.
From the moment we are born, life is one big discovery after another. We're always learning and always finding new things. However, we need to look at the whole thing realistically.
There might very well be invisible fairy folk flying round our houses, and if we could only find them they would grant us all 3 wishes each. Unforunately lack of any evidence at all leaves us in a position where it does not merit absolute focus, devotion and worship. Doing so would be little more than an act of complete lunacy.
You'd think though, that after several thousand years of absolute persistance something thought to exist would yield evidence, and yet in all that time, all the persistance and absolute devotion have yielded nothing whatsoever. Not a bean.
There must come a time where those people should loosen their grip, knowing deep inside that what they want so bad, what they wish in their heart was true, just isn't so.
It is no wonder that all these dreams are all about everything that man cannot have. A mass of sweet and innocent virgins, a city made of gold and gemstones free from nasty people like rapists, murderers and homosexuals. Every 'afterlife' consists of something that is not natural to man, has never been and will never be. All of these of course "imagined" at a time when things were so much worse off. A time when killing innocent people was commonplace, where diseases were rife, where the evil side of humanity had room to breathe.
For the majority it is a very hard dream to wake up from, especially once that dream has been force fed into the minds of the very young and the mentally fragile.
There might be a god, there might be hundreds of gods. There might be flying bananas and a world full of sexually rampant alien women who all look like playboy centrefolds, but right now it cannot be taken seriously, and you know it.