We think in much too human terms and tend to fit God into our own limitations as well. Who is to say whether 6000 or 14 billion years is too long or too short to create a universe? Either scale of time divided by the infinite nature of God approaches zero. God gave us rational minds to worship and discover His creation. Before human beings with a God-given intellect, no other creature pondered its existence or had the capacity to even conceptualize history, space, time, or mortality.
The problem arises due to the vast discrepancy between YEC and modern dating. It’s not like Genesis recounts a 12 billion year old universe and modern science proposes 13.7 billion years; if that were the case, there would be room for actual debate. Both sides would be thinking, “hmm, maybe we’re off by a little bit.” But the difference between 6000 and 13.7 billion years is so vast that the two theories cannot really be reconciled. YEC scientists seem to take anomalies and extrapolate every single one of them to fit into a 6000 year old earth. They will find a few dinosaur bones with soft tissue (anomalies) and then propose that the dinosaurs died within the last 6000 years. Or they will claim the Grand Canyon was caused by geologic fractures during the flood. But they will then decry any modern science (the vast majority of other research performed) which proposes long ages as anti-Biblical, as if all of those scientists entered their fields for the sole purpose of undermining Genesis.
As difficult as it may be, one must be open to and consider the great similarities between Genesis and other Mesopotamian creation stories such as the Enuma Elish and the Epic of Gilgamesh. However, we do hold by faith that Genesis accurately conveys the purpose of God’s creation and its inherent beauty and goodness.