Handedness
Always there are always more right-handed people in a population. But, all the same, the world has many important scripts which are written right to left. Some, like Arabic, Hebrew, Persian and Urdu are widespread and important. It is worth remembering that in the past most people could not write. Even in England in 1800 many men signed their marriage certificate with an X, because they were illiterate (could not write). Widespread literacy came in the 19th century. So, when writing was invented, it was a few thousand years ago, and only the priests and officials needed to use it. Almost all monuments of that time used pictures as well as words, so that the mass of people could understand them. Much that we take for granted, like spaces between words (!), was not there at the start of writing, and several oriental languages can be written top-to-bottom as well as horizontally.