Why Don't All Food Cans Have Pull Tabs?

You can open a can with a can opener, but a can with a pull tab is even easier to open. So, why don't more cans come with pull tabs?

Related Keywords

Pennsylvania ,United States ,Ohio ,Dayton ,Iron City ,American ,Ermal Ernie Fraze ,Tom Crothers , ,Iron City Beer ,Easy Open Cans ,Tabs Aren T ,