The Neomark cracking issue was seen in the first few runs of balls made. As with any new manufacturing process, there is a bit of tweaking. It has taken another company several years to iron out issues with their new plant, and another has issues with balls cracking in the box before you get a chance to drill them. Most don't realize the complexity of the machinery that is used to make bowing balls. There are filters, check valves, pumps, nozzles, flow control regulators and on and on. One clogged filter can change the mixtures enough that things can get messed up. Early on sometimes these issues that need to be carefully watched don't become apparent.
Simple answer, notice the pictures of this failure are all TX1 and SX1? The first balls manufactured.
Do you see pictures or hear stories of any of the other balls doing this currently? No. All I know of other than the aforementioned balls is an SR2 and RX1. That is 2 balls out of the thousands upon thousands manufactured. Go to a distributors warehouse and check out the defective/return area. You will see how few balls are returned with issues.
This isn't simply my opinion, nor am I feeding you a line. The quality is there, you just need to know the indicators to look for.