I think they are trying to discredit any and all tools that are used to prove that the earth is older than about 50,000 years old. Radioactive elements decay at a constant rate, and hence are reasonably accurate.
What they say about carbon dating being way off is a crock of bulls***. As any ninth-grade science student knows, carbon-14 (which is used in carbon dating) decays at a constant rate. And the products are predictable. So, by measuring the concentrations of products, it is accurate to within reasonable limits. What the Witlesses say (with zero proof to back it up) is that one cannot tell within several orders of magnitude how old something is by measuring the concentration of decay elements. That's a blatant lie.
Also, if the earth was only 50,000 years old as the Witlesses claim, then why is it not all molten? A mass the size of the earth takes billions of years to cool through, and we have a crust that is several billion years old. The 20 miles or so of crust insulates the interior of the planet, slowing the cooling down some more. If the earth was only 50,000 years old as the Witlesses claim, the crust would still be extremely unstable and thin. For sure, it wouldn't be thick enough to insulate us from the core's extremely hot temperatures, and life would be nearly impossible. It would also be subject to upheavals. Not to mention that in 50,000 years, there would still be a fair amount of matter still raining down that would be capable of smashing into the crust with enough force to destroy the whole crust. In fact, this has happened while the earth was forming. One such hit was enough to create our moon!
And there is the problem with light traveling at 186,282.397 miles per second. At this speed, it would take more than 10 billion years to cross the universe. There is no reason to expect all the light waves/particles (it's still in the air as to which) to be filled in; nor would light travel those distances instantaneously. Light from distant quasars takes more than a billion years to reach the earth, and some of the farthest ligth now being picked up by the Hubble telescope was en route for more than 10 billion years. Is this only 50,000 years old? Is light's speed so unreliable that top scientists cannot tell how old the universe is?
No wonder the Watchtower Societh wants children to be so tired on Fridays. They will not pass these science tests, which are showing up during high school and even junior high. The Tower wants people to flunk astronomy and physics. Then, they can pull scams like this without people asking questions. I only wish I could educate Nigerians at the administrative level so I could make sure every Nigerian child knows these basic facts by the seventh grade. I wonder what the Tower would do if they see 475,000 Bible studies discontinued and another 280,000 S-77 forms all coming out of Nigeria because of this.