Personally these are quite strange requirements for an air hostess, and quite discriminating. What might be appealing to one may not be appealing to someone else. Moreover how's marital status likely to affect how good a air hostess you are?

Answers:

1. - Couldn't trust you more. I realize how the person must be of a certain size/build due to the nature from the environment that they must function in and of course proper hygiene, but personal attractiveness does seem to be a discriminatory area. Also, men appear to excluded from several jobs. Is this because they aren't applying, or simply because they aren't being hired?

2. - Some airlines use the younger, more appealing flight attendants because of the image they would like to portray. The youth may symbolize energy and who doesn't want to be served by a stylish person? I agree that beauty is incorporated in the eye from the beholder and what one thinks is beautiful may not be beautiful in someone else's eye but some countries don't have laws against age discrimination. I know that in some countries, a flight attendant is a highly coveted and highly respected position. Lots of people apply to become one. Therefore when there are so many applicants, the airline could be more selective on whom installed on their flights.

As for marital status, the only thing I will guess is the fact that when you are single, you have fewer obligations. Once you are married, your priorities change and for those who have children, your priorities are different too.

3. - Within the globe, requirements such as these are increasingly rare. In the developing world, that is about 40 years behind the times regarding aviation, this type of abuse is still practiced by some airlines. Eventually these countries will most likely meet up with the 21st century.
Source: http://becomeflightattenfant.com