In Tallinn, the ticket inspectors are still there though. And you can get fined if you are a local resident and should ride free, but forgot to "buy" your free ticket by swiping the RFID card in the bus. Even after several court rulings undoing such fines.
However, the idea of free public transport, is not that bad, if feasible. In Tallinn, it used to be heavily subsidized anyway, with only ~20% of the money coming from ticket sales (IIRC). They are also planning to extend this to railways within the city, which are operated by private companies - would definitely make some commutes quicker.