It's called a transition period, and they're never perfect. There were four choices and after analyzing the market a decision was made so the greatest number of people could charge their AirPods.
Option 1: Include a USB A cable for the billions of people who have a USB A charger of some kind, i.e. a pre 2016 Mac or PC, or any other USB A wall charger (Apple or any other manufacturer). Result on MR: Wah... along with stomping of feet, and tiny whines about Apple not serving their (relatively) small number people that have a 2016 MBP who now have to buy a cable or $4 adapter. Apple is doomed, TC should be canned, buh-blah, buh-blah, buh-blah.
Option 2: Include a USB C cable for the (relatively) small number of lucky people that have a 2016 MBP. Result on MR: Wah... along with stomping of feet, and tiny whines about there being a few billion people who only have devices with USB A charging capability (computers and USB A wall chargers) who now have to buy a cable or $4 adapter. Apple is doomed, TC should be canned, buh-blah, buh-blah, buh-blah.
Option 3: Include both USB A and USB C cables. Well, that's dumb as rocks and a load on the e-waste situation. Still, because of that, on MR there will be: Wah... along with stomping of feet, and tiny whines about Apple being wasteful and not sensitive to the environment. Apple is doomed, TC should be canned, buh-blah, buh-blah, buh-blah.
Option 4: Include no cables; and even reduce the price. Result on MR: Wah... along with stomping of feet, and tiny whines about Apple being cheap and greedy and not caring about their customers because people now have to use the a USB A to lightning cable they probably have laying around, or, buy a cable. Apple is doomed, TC should be canned, buh-blah, buh-blah, buh-blah.