Jolly Girl - whilst you have humans in cockpits you will experience the failings of the human species - we are not perfect, we make errors of judgment, we are not the same animal from day to day and we are often guilty of believing our own press 'I'm a pilot of course I can do x'
All the legislation in the world can't remove the operational pressures (some external, some internal) that crews feel (or perceive that they feel) to get the job done, whether it is taking friends on a jolly day out or getting a seriously ill patient to hospital.
Training and education are the main weapons to combat these failings but these cost money and need to be proactive to ensure a culture of safety not reative as a sticking plaster once something has gone wrong.
The biggest pressure is often the financial one but unless you want to stop people making a living from aviation that will never go away and people will always be willing to cut corners and take risks to make money - probably the biggest human failing of them all.