Having free travel on public transport is fine if you have public transport available within walking distance of where you are. As Eliza pointed out, there are many people who do not live near enough to buses or trains, so unless they have obliging friends and family or can afford taxis, they are stuck.

There are also moves afoot to make people pay a certain amount for journeys using their bus passes. If this results in elderly people taking up driving again after they have not driven for a while, it could lead to more accidents.