So you're in an interview with Qatar Airways and they ask you the question "state why you wish to join Qatar Airways or any of its subsidiaries?"
In my opinion, there is no generic right or wrong answer, it will really come down to how you answer the question in the moment.
But, if I were to give some advice, I'd say try to break it down into two parts:
- What the company is going to get out of employing you
- What you hope to get out of working for Qatar Airways
And then in your answer, try your best to align the two .
For example, you could say that you hope to have a long and successful career, learning about customer care and delivering the highest level of service (things that you may have an interest in, but which the company will certainly want to see in you).
Then you could mention how other motives are the opportunity to travel and meet people from around the world (not a company objective, but shows that you're the right kind of person for the role potentially).
Hope it goes well for you!