I think you are missing the point. A person who hires an aircraft for public transport has a reasonable expectation of arriving safely. Like any form of public transport, a taxi, a bus, a train or an aircraft there have to be certain safeguards in place to ensure that unnecessary dangers have been eliminated, hence an AOC. A Flying club is a group of private individuals who are prepared to accept that their activity may have an element of risk attached and can make their mind up whether or not to accept it. The AOC holder has to pay for the certification process whereas the flying club is left to their own devices.
The unsuspecting punter who comes in the door for a trial flight has no concept of the different levels of supervision and certification, but probably assumes they are the same. If you go scuba diving or bungee jumping you will be made aware of the dangers, maybe flying clubs should follow a similar process.
In practice there is no reason why a flying club flight should not have a comparable level of safety to an AOC operation however; it has not been subject to the same level of scrutiny and cost, and there remains an uncertified element of risk.