It doesn't say it was created 6,000 years ago, but it implies it from the series of events. You can follow the lineages down from Adam and Eve to Moses, Abraham, and other major biblical characters, which we can historically place.
That means for you to accept this skull isn't a hoax, you have to accept that somehow at least 1.8 million lost years occurred between Adam and Eve and Jesus. Why would the bible magically omit 1.8 million years? How could any society, much less the jews, survive 1.8 million years?
Then you'd have to admit that Adam and Eve looked something like Australopithecus.
Which then would require you to believe that god was somehow unpleased with his first models of humans, destroyed them and created hundreds of new versions until he finally got it 'right' about 6,000+ years ago.
If you can fit all these things into a nice, logical model, then I applaud your mental gymnastics.
As you can see above, the history of the homo genus spans millions of years, which no matter how you count it, doesn't match with the biblical lineages traced from Adam and Eve. Either they weren't actually the first humanoids god created, or there's a massive 1.8 million+ year gap in the bible and the lineages are just wrong.