Humans began to understand the true scale of geological time in the early 19th century. The probable depth of cosmological time and the extent of the history of the human species have come to light only within our own lifetimes.
That is a lot to absorb and, not surprisingly, many people refuse to absorb it. Nearly every attack on evolution - whether it is called intelligent design or plain creationism, synonyms for the same faith-based rejection of evolution - ultimately requires a foreshortening of cosmological, geological and biological time.
Humans feel much more content imagining a world of more human proportions, with a shorter time scale and a simple narrative sense of cause and effect. But what we prefer to believe makes no difference. The fact that life on Earth has arrived at a point where it is possible for humans to have beliefs is due to the steady ticking away of eons and the trial and error of natural selection.
The only intelligent discussion I have found on Intelligent Design (please note the sarcasm) may be found here.