xfeed,
That's a very contentious line to take if you do indeed wish a career within the airline industry.
The passenger is, along with cargo, the revenue payer. Without them we wouldn't get off the ground and wouldn't get paid, don't forget that. As such they have a right, along with any other service industry, to complain about poor or sub standard service. I wouldn't begrudge them that at all as I have been on the receiving end of poor service many times when traveling.
If a passenger complains to me and I feel their complaint is just then I will explain the reasons for the 'event', for want of a better word, apologise as best I can on behalf of the company and direct them to write their complaint in to the company.
Most people just want to be heard when things go drastically wrong and giving them the time to be heard can often be 95% of the solution.
NEVER, NEVER, NEVER alienate your revenue payers, it will come back to bite you.