Public transport is subways, buses, commuter trains, trolley cars. When they are privatized, it means they are run by private companies instead of a government agency. If they are inefficient, then they do not work right. The bus schedules can be off, trains breakdown, subways freeze, people are late for work, traffic is jammed... etc.
Just think of a great big metropolitan city and all the traffic problems. One city bus with a flat tire because of bad maintenance and misappropriated funds can cause 45 people to miss connecting transfers and/or be late to dr appointments and jobs and school rooms. Chain reactions, domino effects, backlashes, and bad management. The government can no longer tell them what to do, because the private company has control.