There was a time when almost all light airplanes had tailwheels. They were cheaper and lighter to build than nosewheel airplanes and, besides, “we’ve always done it this way,” has always been very powerful in guiding design decisions. In the little airplane world, save for a few non-conformists such as the Ercoupe, Navion and Bonanza, tailwheels ruled.
This is a companion discussion topic for the original entry at https://www.avweb.com/features/used-aircraft-guide-piper-tri-pacer