Hornady is in business to make money. Anyone involved in sales knows that it is a "numbers game". If you ain't pitching, you ain't selling. If you ain't selling, you ain't making money. And after you sell so much of one thing, you need to be pitching something new... Same reason there are eighty eleven flavors of Italian salad dressing on the grocery shelf...
I have no personal interest in the 6mmARC just like I have no personal interest in the 6.5 Creedmoor. However, I am glad that they are selling because that means that the ammunition and firearms manufacturers are making money. Which increases the likelihood they will still be around to produce the things that I am personally interested in...
Bingo! Never could understand all the flack anything new catches here. It's all good, and almost everything is interesting to me even if I don't have any use for it right then.
