Oh, I got the point. The ultimate goal is to raise money for the airline: I think enhancing one's product value is a better strategy than selling billboard space on a flight attendant apron.

This is really a "tempest in a teapot", as the saying goes. Flight attendants already hawk credit cards non-stop ("Sky miles"), sell overpriced candy, distribute napkins with company logos, etc. Any airplane with a tv screens in the cabin show advertisements between shows, some planes have advertisements on the tray tables.

Heck, half the passengers are walking billboards for "Nike", "Pink", sports teams, etc.

I just don't see what the fuss is about. An apron with advertising that everyone is just going to ignore anyway? I'm more amazed that a company would pay for the privilege.