Because the false science, called the evolution theory, does not believe the Biblical global flood had happened for why they base the "accuracy" of there dating results on that faulty assumption that there was no global calamity within the last 55,000 years. So by believing they have accurate dating results, is why they are getting inconsistent carbon dating results which they purposefully gloss over and explained away.
Like carbon dating a living mollusks as 2,300 years old dead. Evolutionists contends that science does not carbon date living things, but they did and all the naysayers have to do is search the internet for that.
Same as carbon dating dinosaur bones which ranges different results of 1,000 years to 100.000 years; evolutionists contends that science knows better than to carbon date dinosaur bones BUT science did it anyway.
The world that serves sin is striving to cover up the Biblica evidence of the global flood.
I did not use my reference to the Biblical global flood to debunk that at all but the Bible proves by genealogies in the Old & New Testament that the earth is only 6,000 years old, which God started to create that earth on that 2nd day by creating that firmament ( gravity ) that divide the water from the water in creating a water planet with the upper atmosphere aka the sky or the first heaven.
But note how God did not say it was good on the 2nd day? He said it was good on every other 6 days of creation but not on the 2nd day and that is because He was not done creating the earth until the 3rd day for when he said it was good then.
That means the earth was not there in Day One as that light that was created was to establish "the beginning" by its evening and morning that first day.
That also means the heavens, aka the universe, was not there in Day One for why it was created on Day 4 for the purpose of giving signs, seasons, days and years to the earth that 4th day.
So God created the celestial bodies by His words in that 4th day and commanded her lights to shine on the earth that 4th day and so science cannot use the speed of light t tell us how old the universe is when God commanded her lights to shine on that earth that 4th day.
You have to consider what can throw off the rate of decay. It is an assumption that there was no global calamity for why they deny the Biblical global flood and yet Jesus affirmed it as a warning to Christians to be ready to leave all behind or else in Luke 17:26-33.
So what can cause the Biblical global flood if the earth was really young as projected at 6,000 years? look at the asteroid impacts on the moon. Did not science noted that the moon has been slowly moving away from the earth? When did it happen> According to the Bible, 4,000 years ago when using discernment.
The moon controls the rising and the lowering of the tides, right? Since the Bible testified that earth was like a greenhouse world with plants growing even near the poles, like the Tundra regions, and it was being watered by a mist, then what would cause it to rain for the first time? The moon being impacted by asteroids in starting its movement away from the earth, to cause the mist to rise and condense into clouds to rain for the first time on earth.
And then you have to discern what broke up the fountains of the deep? Asteroid impacts on the earth. "Science" got it wrong by designating these asteroid impact happening at different time periods rather than all at ounce at the time of the Biblica global flood. So of course, sediments from the deluge and its receding will throw off the perceptions as if they happened at different time periods rather than consider how a biblical global flood can give that illusion when that false science refuse to acknowledge it.
I have to give you a link to that movie "Expelled; No Intelligence Allowed" to take you to the video section of the forum since that is the only place allowed for videos, but this will show how the world does suppress the truth in science.